2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

November 2018

Alternate Formats Available

2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Prepared for: King County Wastewater Treatment Division Department of Natural Resources and Parks

Submitted by: Wendy Eash-Loucks Marine and Sediment Assessment Group King County Water and Land Resources Division Department of Natural Resources and Parks

2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Citation King County. 2018. 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results. Prepared by Wendy Eash-Loucks, Water and Land Resources Division. Seattle, Washington.

King County Science and Technical Support Section i November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Table of Contents

Executive Summary...... vi 1.0 Introduction ...... 1 2.0 Site Description and Monitoring History ...... 2 2.1 1995 Monitoring Event ...... 3 2.2 1997 Monitoring Event ...... 4 2.3 1999 Monitoring Event ...... 5 2.4 2001 Monitoring Event ...... 6 2.5 2011 Monitoring Event ...... 6 3.0 2017 Sediment Monitoring Event ...... 8 3.1 Sampling Design ...... 8 3.2 Data Quality Objectives ...... 8 3.3 Sample Collection ...... 10 3.3.1 Station Positioning ...... 10 3.3.2 Sampler Deployment and Retrieval ...... 11 3.3.3 Sample Processing ...... 11 4.0 Laboratory Analysis ...... 13 4.1 Sediment Chemistry ...... 13 4.1.1 Conventionals ...... 13 4.1.2 Metals ...... 14 4.1.3 Organic Chemicals ...... 14 4.1.4 Sediment Chemistry Quality Assurance/Quality Control...... 14 4.2 Sediment Toxicity ...... 18 4.2.1 Sediment and Water Quality Parameters ...... 18 4.2.2 Acute Amphipod Bioassay ...... 19 4.2.3 Acute Larval Echinoderm Bioassay...... 19 4.2.4 Chronic Juvenile Polychaete Bioassay ...... 20 4.2.5 Bioassay Test Quality Assurance/Quality Control ...... 21 4.3 Benthic Taxonomy ...... 21 5.0 Sediment Chemistry Results...... 22 5.1 Conventionals ...... 22

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5.2 Metals ...... 23 5.3 Organic Chemicals ...... 24 5.3.1 Polar Organic Chemicals...... 24 5.3.2 Nonpolar Organic Chemicals ...... 26 6.0 Sediment Toxicity Data...... 29 6.1 Acute Amphipod Bioassay ...... 29 6.2 Acute Larval Echinoderm Bioassay ...... 29 6.3 Chronic Juvenile Polychaete Bioassay ...... 31 7.0 Benthic Taxonomy Data ...... 33 7.1 Benthic Community Indices ...... 33 7.1.1 Abundance ...... 33 7.1.2 Biomass ...... 34 7.1.3 Richness ...... 35 7.1.4 Shannon-Wiener Diversity ...... 36 7.1.5 Pielou’s Evenness ...... 36 7.1.6 Swartz’s Dominance ...... 36 7.2 Comparison to Other Datasets ...... 38 8.0 Summary ...... 40 9.0 References ...... 42

Figures

Figure 1. South Wastewater Treatment Plant and outfall locations with predominant tidal currents indicated (based on NOAA et al., 2009)...... 2 Figure 2. 1995 South Plant NPDES sediment monitoring program sampling stations...... 4 Figure 3. 1997 South Plant NPDES sediment monitoring program sampling stations...... 5 Figure 4. 1999 and 2001 South Plant NPDES sediment monitoring program sampling stations...... 6 Figure 5. 2011 South Plant NPDES sediment monitoring program sampling stations...... 7 Figure 6. 2017 South Plant NPDES sediment monitoring program sampling stations with predominant tidal currents based on NOAA et al. (2009)...... 9 Figure 7. Particle size distribution of sediment samples collected near the South Plant outfalls in 2017 and 2018...... 23

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Figure 8. Summary of 2017 and 2018 South Plant sediment monitoring results highlighting exceedances of the SQS criteria for benzoic acid...... 26 Figure 9. Benthic invertebrate abundance (average of three replicates per station) by major taxonomic group at eight stations surrounding the South Plant outfall...... 34 Figure 10. Benthic invertebrate biomass (average of three replicates per station) by major taxonomic group at eight stations surrounding the South Plant outfall...... 35 Figure 11. Benthic invertebrate richness (average of three replicates per station) by major taxonomic group at eight stations surrounding the South Plant outfall...... 36

Tables

South Plant Outfall alignment coordinates (NAD83)...... 3 2017 sediment sampling station locations (NAD83) and depths...... 9 Sequence of sediment chemistry and toxicity testing...... 13 Bioassay sediment information including collection date, hold times, and percent fines...... 18 Summary of sediment conventional parameters near the South Plant outfalls collected in 2017 and 2018...... 22 Summary of sediment metals concentrations near the South Plant outfalls collected in 2017 and 2018...... 24 Summary of polar organic concentrations near the South Plant outfalls collected in 2017 and 2018...... 25 Summary of PAH concentrations near the South Plant outfalls collected in 2017 and 2018...... 27 Summary of phthalate concentrations near the South Plant outfalls collected in 2017 and 2018...... 27 Summary of PCB Aroclor concentrations near the South Plant outfalls collected in 2017 and 2018...... 28 Comparison of amphipod bioassay results to SMS Marine Biological Criteria (SQS, CSL, and performance standards)...... 29 Comparison of standard echinoderm bioassay results to SMS Marine Biological Criteria (SQS, CSL, and performance standards)...... 30 Comparison of screen tube echinoderm bioassay results to SMS Marine Biological Criteria (SQS, CSL, and performance standards)...... 30

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Comparison of dry weight Neanthes 20-day growth to SMS Marine Biological Criteria (SQS, CSL, and performance standards)...... 31 Comparison of ash-free dry weight Neanthes 20-day growth to SMS Marine Biological Criteria (SQS, CSL, and performance standards)...... 32 Summary of conventional parameters and benthic indices of samples (average of three replicate samples) collected near the South Plant outfall...... 37 Summary of South Plant benthic indices compared to Ecology’s long-term Puget Sound benthic monitoring stations (collected from 1989 to 2015)...... 38

Appendices Appendix A: Sample Collection Details Appendix B: 2017 Sediment Chemistry QA/QC and Analytical Results Appendix C: 2018 Sediment Chemistry QA/QC and Analytical Results Appendix D: Appendix E: Sediment Chemistry Results Compared to Sediment Standards Complete Bioassay Results Appendix F: Complete Benthic Taxonomy Data

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EXECUTIVE SUMMARY King County conducted sediment sampling and analysis near the South Plant’s marine outfalls to fulfill the sediment monitoring requirement of NPDES Permit No. WA0029581. Sediment samples were collected from eight stations in September of 2017 and analyzed for conventionals and chemicals regulated under the SMS. Additionally, three replicate benthic taxonomy samples were collected at each of the eight stations for identification and enumeration. Based on the initial sediment chemistry results, five stations were resampled in May 2018 for repeat chemistry analysis in addition to acute and chronic toxicity testing to refute or confirm initial exceedance results.

The initial sediment chemistry results showed that concentrations of those chemicals regulated under SMS were all well below their respective chemical criteria in all eight samples, with one exception. Benzoic acid was elevated above the combined SQS/CSL at five stations. The abnormally high benzoic acid sediment concentrations appears to have been a widespread occurrence in the Central Basin of Puget Sound based on other King County sediment monitoring results collected in 2017. The second round of sediment chemistry results indicated that concentrations of all chemicals were well below their respective chemical criteria at the five stations that initially had exceedances with the exception of one station (STP460S), which again exceeded the SQS/CSL for benzoic acid. Station STP460S, as well as the other four stations sampled in May 2018, passed the biological/toxicity tests. These results indicate that there were no apparent biological effects and that all stations passed the SMS. Additionally, benthic taxonomy results indicate a moderately diverse benthic community, typical of deep, depositional areas in Puget Sound. There was no over-abundance of pollution-tolerant species, molluscs were the most abundant phyla, and the sea cucumber Molpadia intermedia was the most conspicuousResults of the taxa. combined South Plant sediment chemistry, toxicity, and benthic community analyses do not indicate a potential biological impact of effluent to the sediments surrounding the outfalls.

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1.0 INTRODUCTION This report presents results of the September 2017 sediment sampling event at King County’s South Treatment Plant outfalls. This report includes project background, descriptions of sampling and analytical methodologies, and results of sediment chemistry, toxicity, and benthic community analysis. Appendices to the report include sample coordinates and collection information, complete chemistry results with quality assurance review of chemistry data, complete sediment toxicity results with quality assurance review of toxicity data, and complete benthic taxonomy data.

This work was performed to meet the sediment monitoring requirement of Special Condition S9 of King County’s NPDES South Wastewater Treatment Plant Permit No. WA0029581, issued by Ecology effective August 1, 2015. Condition S9 states, that the permittee must follow the guidance provided in the Sediment Source Control Standards User Manual, Appendix B: sediment sampling and analysis plan (Ecology, 2008) (now obsolete and replaced with the Sediment Cleanup User’s Manual II [SCUM II] [Ecology, 2017]), and recharacterize sediment quality in the vicinity of the discharge location (Ecology, 2015).

Based on these requirements, a draft sampling and analysis plan (SAP) was submitted to Ecology in November, 2016 and finalized in July, 2017 (King County, 2017). All work on this project was performed in accordance with the SAP. Project data were submitted in November 2018 to Ecology’s EIM database under Study ID: South_Plant_2017-18.

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2.0 SITE DESCRIPTION AND MONITORING HISTORY The South Wastewater Treatment Plant (South Plant) is located in the city of Renton near the Green River, 13 miles upstream of the river’s mouth at Elliott Bay (Figure 1). The plant began operation in 1965, providing secondary wastewater treatment with a capacity of 24 million gallons per day (mgd) of average wet-weather flow. At that time, treated effluent was discharged into the Green River near Fort Dent Park. The plant was expanded in 1986 to 72 mgd and a new effluent transfer system was completed to remove discharges to the Green River and carry treated wastewater 12 miles to the current deep water outfalls in Puget Sound. The plant was again expanded in 2001 to its current capacity of 115 mgd of average wet-weather flow and 325 mgd of peak wet-weather capacity.

Figure 1. South Wastewater Treatment Plant and outfall locations with predominant tidal currents indicated (based on NOAA et al., 2009). Net flow is in a northerly direction.

Secondary treatment at the South Plant consists of screening, grit removal, primary sedimentation, air-activated sludge, secondary sedimentation, disinfection by chlorination,

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and anaerobic digestion of solids. Effluent is discharged to Puget Sound through twin outfalls that extend approximately 10,000 feet offshore of Duwamish Head at a depth of - 625 feet referenced to mean lower low water (MLLW). For nearshore protection, the initial portions of the outfalls are supported by legs and the remainder of the outfalls rest along the seafloor in a shallow trench. The diffusers, located at the end of the outfalls, are approximately 500 feet in length and approximately 1,000 feet apart. Bathymetry around the outfall diffusers is relatively flat, with depths ranging from approximately -620 to -630 feet MLLW. Outfall alignment coordinates are shown in Table 1.

South Plant Outfall alignment coordinates (NAD83). Location Northing Easting Latitude Longitude End of North Diffuser/Pipe 224090 1247169 47.603167° -122.427472° Start of North Diffuser 223958 1247660 47.602833° -122.425472° End of South Diffuser/Pipe 222667 1247133 47.599250° -122.427500° Start of South Diffuser 222600 1247632 47.599111° -122.425472°

Past monitoring results have shown that sediment in the vicinity of the South Plant outfalls is comprised mainly of silt and clay with low amounts of coarse material. Percent fines generally range from 80 to 95% and organic carbon values in sediment generally range from 2 to 2.5%, which is typical for deep, depositional areas of Puget Sound.

Sediment monitoring at the South Plant outfalls was previously conducted on a biennial basis, with sediment samples collected and analyzed in 1995, 1997, 1999, and 2001. Sediment monitoring results from these four sampling events were published in King County’s annual water quality status reports (King County 1997, 1999, 2001, 2002). Sediment monitoring was not required under the 2004 to 2009 NPDES permit for the South Plant, but was once again required and conducted in 2011 (King County, 2012).

2.1 1995 Monitoring Event Sediment samples were collected from three stations in the vicinity of the South Plant outfalls in October of 1995 (Figure 2). Samples were collected from the 0- to 2-centimeter (cm) depth stratum and submitted for analysis of trace metals, semivolatile organic compounds, chlorinated pesticides, polychlorinated biphenyls (PCBs), and conventional parameters. Pesticides and PCBs were not detected in any of the three samples and all detected trace metals’ concentrations were below their respective Sediment Management Standards (SMS) chemical criteria (Ecology, 1995). Concentrations of semivolatile organic compounds in all three samples were below their respective SMS chemical criteria with one exception. The benzoic acid concentration at station LSDS02 was 1,480 micrograms per kilogram, normalized to dry weight (µg/Kg dw), which exceeded the combined Sediment Quality Standard/Cleanup Screening Level (SQS/CSL) of 650 µg/Kg dw. Station LSDS02 was located approximately 1,200 feet north of the northern outfall.

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Figure 2. 1995 South Plant NPDES sediment monitoring program sampling stations.

2.2 1997 Monitoring Event Sediment samples were collected from eight stations in the vicinity of the South Plant outfalls in October of 1997 (Figure 3). Samples were collected from the 0- to 2-cm depth stratum and submitted for analysis of trace metals, semivolatile organic compounds, chlorinated pesticides, PCBs, and conventional parameters. Pesticides and PCBs were not detected in any of the eight samples and all detected trace metals’ concentrations were below their respective SMS chemical criteria. Concentrations of semivolatile organic compounds in all eight samples were below their respective SMS chemical criteria with three exceptions. The hexachlorobenzene concentrations of 1.9 and 1.0 µg/Kg dw detected at stations RT625ND and RT625SD, respectively, exceeded the SQS chemical criterion of 0.38 µg/Kg dw and the hexachlorobenzene concentration of 2.5 µg/Kg dw detected at station RT700NS exceeded CSL chemical criterion of 2.3 µg/Kg dw. Stations RT625ND and RT625SD were located, respectively, at the north and south outfall diffusers and Station RT700NS was located midway between the two diffusers.

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Figure 3. 1997 South Plant NPDES sediment monitoring program sampling stations.

2.3 1999 Monitoring Event Sediment samples were collected from 13 stations in the vicinity of the South Plant outfalls in October of 1999 (Figure 4). Samples were collected from the 0- to 2-cm depth stratum and submitted for analysis of trace metals, semivolatile organic compounds, chlorinated pesticides, PCBs, and conventional parameters. Additionally, benthic community analysis was performed on samples collected from six stations – RT412N, RT625ND, RT700NS, RT625SD, RT412S, and RT2500R. Pesticides were not detected in any of the three samples. While PCBs were detected in all 13 samples, concentrations were well below the SQS chemical criterion of 12 milligrams per kilogram, normalized to organic carbon (mg/Kg OC). Detection limits changed from previous sampling events and the concentrations observed ranged from 0.6 to 1.4 mg/Kg OC. All detected trace metals’ and semivolatile organic compound concentrations were below their respective SMS chemical criteria.

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Figure 4. 1999 and 2001 South Plant NPDES sediment monitoring program sampling stations.

2.4 2001 Monitoring Event Sediment samples were collected from the same 13 stations in November of 2001 as in 1999 (Figure 4). Samples were again collected from the 0- to 2-cm depth stratum and submitted for analysis of trace metals, semivolatile organic compounds, chlorinated pesticides, PCBs, and sediment conventional parameters. Benthic community analysis was again performed on samples collected from the same six stations as in 1999. Chlorinated pesticides were not detected in any of the 13 samples. PCBs were detected in 2 of 13 samples. Detected concentrations of PCBs, trace metals, and semivolatile organic compounds were all below their respective SMS chemical criteria.

2.5 2011 Monitoring Event The goal of the 2011 South Treatment Plant outfall sediment sampling event was to recharacterize sediment quality proximal to the outfalls. Sediment samples were collected in July from the top 10 cm of sediment at eight stations surrounding the two outfalls (Figure 5). Sediment samples were analyzed for trace metals, semivolatile organic

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compounds, PCBs, and sediment conventional parameters. All detected metal concentrations were well below their respective SQS chemical criteria and consistent across all eight stations. Polycyclic aromatic hydrocarbons (PAHs) and bis(2- ethylhexyl)phthalate were the only semivolatile organic compounds detected in the eight stations, while PCBs in the form of Aroclor 1254 were detected at four of eight stations. All samples were below the SMS criteria for the metals and organic compounds analyzed with the exception of bis(2-ethylhexyl)phthalate at station STP625SP. The initial result at that station indicated that concentrations of bis(2-ethylhexyl)phthalate were 116 mg/Kg OC, which exceeded the SMS Cleanup Screening Level of 78 mg/Kg OC. However, the sample was determined to be anomalous based on low levels of bis(2-ethylhexyl)phthalate at the other seven stations, and the sample was re-analyzed in triplicate. The three results averaged 3.5 mg/Kg OC and it was concluded that the original result was not representative and that the actual concentration at the station was below the SMS criterion.

Figure 5. 2011 South Plant NPDES sediment monitoring program sampling stations.

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3.0 2017 SEDIMENT MONITORING EVENT The primary goal of the 2017 South Plant outfall sediment monitoring event was to meet the sediment monitoring requirement of the County’s NPDES permit No. WA0029581. The following sections describe the sampling design and collection process for the 2017 sampling event.

3.1 Sampling Design Sampling for the 2017 South Plant sediment monitoring event was designed to allow a full characterization of sediment quality in the immediate vicinity of the outfall. Eight stations, last monitored in 2011 were initially sampled in September, 2017. These samples were analyzed for sediment chemistry (conventionals, metals, and organics) as well as benthic infauna. As per the SAP, bioassay (toxicity) samples were only to be collected and analyzed in 2018, concurrently with another round of sediment chemistry samples, if initial chemistry results indicated an exceedance of SMS criteria (King County, 2017).

3.2 Data Quality Objectives The data quality objectives of the 2017 South Plant outfall sediment sampling event were to collect data of sufficient quality and quantity to meet NPDES permit requirements and the following study goals:

• quantify sediment chemical concentrations in the vicinity of the outfall and compare them to Washington State SMS; • conduct follow-up sediment bioassay tests to determine the nature and extent of biological toxicity if SMS chemistry criteria are exceeded; and • evaluate the health of the benthic community surrounding the outfall through supplemental benthic invertebrate (infauna) community analysis.

The quantity of sediment chemistry and toxicity data were collected based on NPDES permit requirements to re-characterize sediment quality in the vicinity of the discharge location. Initial sediment samples were collected in September, 2017 from eight stations proximal to the outfalls for the analysis of sediment chemistry and benthic taxonomy (Table 2 and Figure 6). Additional sediment and toxicity samples were collected from five of those stations in May, 2018 in order to meet the second study goal at stations that had SMS exceedances. Chemistry and toxicity analyses were performed on samples collected from the top ten centimeters (cm) of sediment to capture the biologically active zone.

Data collected were of sufficient quality to meet the study goals outlined in the project SAP. The data quality issues of precision, accuracy, bias, representativeness, completeness, comparability, and sensitivity were assessed and project data were considered acceptable

King County Science and Technical Support Section 8 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results for the project needs. Any deviations from the project SAP are outlined in applicable sections of this report (e.g., metals quality control assessment is in Section 4.1.4 Laboratory Analysis - Sediment Chemistry Quality Assurance/Quality Control [QA/QC]) and potential effects of deviations on the dataset are evaluated.

2017 sediment sampling station locations (NAD83) and depths. Station Northing Easting Latitude Longitude Approximate Depth (-ft MLLW) STP820NE 224490 1247431 47.604278° -122.426447° 625 STP460N 224490 1246880 47.604247°° -122.428680° 625 STP625NP 224053 1246735 47.603041° -122.429231° 625 STP610MN 223471 1246989 47.601460° -122.428152° 625 STP570MS 223142 1246446 47.600527° -122.430325° 625 STP625SP 222623 1246704 47.599119° -122.429236° 625 STP460S 222174 1246509 47.597878° -122.429988° 625 STP770SE 221932 1247060 47.597246° -122.427735° 625

Figure 6. 2017 South Plant NPDES sediment monitoring program sampling stations with predominant tidal currents based on NOAA et al. (2009). Net flow is in a northerly direction.

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Analysis of benthic community data is not one of the requirements of the County’s South Plant NPDES permit. King County characterized the benthic community as an added measure of sediment quality in the vicinity of the South Plant outfall. This was done in order to meet the final study goal (set by King County) to: evaluate the health of the benthic community surrounding the outfall through supplemental benthic invertebrate community analysis.

Analysis of the benthic community structure and abundance, along with sediment chemistry and toxicity testing, provides a more complete characterization of sediment quality in the vicinity of the South Plant outfalls. Surface sediment samples were collected for benthic infauna analysis from all eight stations proximal to the outfall. Three replicate samples were collected at each station for a total of 24 benthic samples. For all benthic samples, the entire contents of the grab sample were used.

3.3 Sample Collection Eight sediment chemistry samples and 24 benthic community (taxonomy) samples were collected near the South Treatment Plant outfall on September 14, 2017. Following NPDES permit requirements, five additional sediment chemistry and five sediment toxicity test samples were collected on May 30, 2018 at stations where sediment standards were exceeded in the 2017 samples. All sampling was performed according to guidelines recommended in SCUM II and the Puget Sound Estuary Program's (PSEP) Puget Sound Protocols (PSEP, 1987; Ecology, 2017). Sediment samples were collected using two 0.1 m2 modified, stainless steel van Veen grab samplers deployed in tandem via hydrowire and hydraulic winch from the King County research vessel SoundGuardian. Chemistry samples were collected from the top 10 cm of sediment while benthic infauna samples were collected from the entire contents of a single grab. Sediments were collected from the contents of a minimum of three deployments of the dual grab samplers to obtain the volume needed for required analyses. Sediment chemistry samples were stored on ice in coolers while in the field, and then transported to the King County Environmental Laboratory (KCEL) at the end of each sampling day. Established chain of custody (COC) procedures were followed for this sampling event. All actual sample collection coordinates, difference from target, and penetration depth information is available in Appendix A.

3.3.1 Station Positioning Station positioning for the 2017 South Plant NPDES outfall sediment sampling event employed a combination of a differential global positioning system (DGPS) and positioning software (Hypak) to calculate the position of the van Veen grab samplers as they contact the seafloor. The research vessel employed a Trimble® DGPS, and prescribed station coordinates were entered into the shipboard DGPS laptop computer. During the sampling event, the shipboard navigational system utilized the differential data transmissions from regional Coast Guard base stations to automatically correct its GPS satellite data. The GPS antenna is A-Frame-mounted above the sampler descent line to achieve a more accurate coordinate fix above the sampling point.

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Upon contact of the grab samplers with the bottom, the coordinate data representing the actual sediment grab impact point was electronically recorded in real time. Positioning information included local time and date that a position is recorded, comments, and coordinate data in both latitude/longitude and NAD 83 State Plane formats.

All samples were collected within 18.3 feet (5.6 m) of the target coordinates.

3.3.2 Sampler Deployment and Retrieval Two 0.1 m2, modified, stainless steel van Veen grab samplers were deployed in tandem at each sampling station. The grab samplers were lowered at a controlled speed of approximately 30 meters per minute until they approach the bottom, at which time the speed was decreased to approximately 10 meters per minute to minimize potential bow wake activity and subsequent bottom disturbance. After the grabs tripped upon reaching the bottom, they were raised slowly to allow gentle and complete closure of the sampler jaws to avoid sample disturbance and loss. Once clear of the bottom, the ascent speed was increased to approximately 30 meters per minute. Acceptable grabs had the following characteristics:

• not overfilled to the point where there is evidence of sample loss around the access doors; • overlying water was present, indicating minimal leakage; • overlying water was not excessively turbid, indicating minimal sample disturbance; and • a minimum acceptable sample penetration depth had been achieved (11 cm).

All samples used for analysis were full (17 cm) with no indication of a loss of sample. Care was taken to extract sediment from the most undisturbed center portion of each grab without collecting sediment for sediment chemistry analysis that had touched the sides or bottom of the grab. Overlying water within the grab was carefully siphoned off of the sediment surface for all acceptable samples.

3.3.3 Sample Processing Prior to any subsampling, sediment aliquots were collected for analysis of total sulfides. The sulfide samples were first collected from the top 10-cm of sediment in the first chemistry grab using a stainless steel spoon and placed directly into the appropriate sample containers without homogenization. The remaining top 10-cm of undisturbed sediment from the same grab was collected and then placed in a stainless steel bowl. Sediments were collected from the 0- to 10-cm depth stratum using a stainless steel spoon. When sufficient sediment for all analyses had been collected, the sediment in the stainless steel bowls were thoroughly homogenized. After homogenization, sediment aliquots were transferred to appropriate laboratory containers as outlined in this projects sampling and analysis plan (King County, 2017).

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All sample containers were stored in an insulated cooler containing ice immediately after collection to maintain the samples at a temperature of approximately 4° Celsius until delivery to the laboratory. At the end of each sampling day, all samples were transported to KCEL.

Sediment from each acceptable benthic taxonomy replicate grab was flushed with ambient seawater through a 1.0-millimeter sieve to remove all fine material. The material remaining on the sieve was transferred into appropriate-sized plastic containers using a minimum amount of seawater. A 10% solution of buffered formalin was added to the sample to preserve all tissues prior to sealing the container. Benthic taxonomy samples were labeled both on the inside and outside of the container, then recorded on chain of custody forms, and placed in coolers for safe shipment to the contract laboratory within 96 hours. Benthic samples were handled as recommended by PSEP and SCUM II protocols (PSEP, 1987; Ecology, 2017).

The grab samplers were decontaminated between sampling stations by scrubbing with a brush and ambient sea water, followed by a thorough in-situ rinsing. A separate stainless steel bowl and spoon was dedicated to each sampling station, precluding the need for decontamination of this equipment.

While in the field, all samples were under direct possession and control of King County field staff. For COC purposes, the research vessel was considered a “controlled area.” Each day, all sample information was recorded on a COC form. This form was completed in the field and accompanied all samples during transport and delivery to the laboratory each day. Upon arrival at the KCEL, the sample delivery person relinquished all samples to the sample login person. The date and time of sample delivery was recorded and both parties then signed off in the appropriate sections on the COC form. Once completed, original COC forms were archived in the project file.

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4.0 LABORATORY ANALYSIS Eight sediment samples collected in September 2017 near the South Plant outfalls were analyzed by the KCEL for conventional parameters and those metal and organic parameters regulated under SMS. In addition, 24 benthic taxonomy samples were analyzed by EcoAnalysts (contract laboratory). Five of the September 2017 sediment chemistry samples exceeded an SMS. Therefore, a second round of sampling at those five station was completed in May 2018, which included additional sampling and analysis for sediment chemistry and toxicity by KCEL (Table 3).

Sequence of sediment chemistry and toxicity testing. Initial Toxicity Additional Chemistry SMS Test Chemistry Station (Nov. 2017) Exceedance (May 2018) (May 2018) STP820NE Yes ✓ ✓ ✓ STP460N No ✓ STP625NP No ✓ STP610MN Yes ✓ ✓ ✓ STP570MS Yes ✓ ✓ ✓ STP625SP No ✓ STP460S Yes ✓ ✓ ✓ STP770SE Yes ✓ ✓ ✓

This section summarizes the types of analysis and tests performed by both KCEL and EcoAnalysts, methodologies used, and associated QA/QC procedures followed.

4.1 Sediment Chemistry A complete list of parameters analyzed and target detection limits/quantitation limits can be found in the project SAP (King County, 2017).

4.1.1 Conventionals Conventional sediment parameters included ammonia, particle size distribution (PSD), total organic carbon (TOC), total solids, total volatile solids, and total sulfide. Percent solids and TOC analyses were performed to provide data necessary to normalize sediment data to dry weight and organic carbon (OC), respectively. Total solids analysis was performed according to Standard Methods (SM) 2540-G (APHA, 2012), which is a gravimetric determination. Total volatile solids analysis was performed on all samples according to EPA 160.4, which is also a gravimetric test. TOC analysis was performed according to EPA Method 9060/SW-846 (EPA, 1995), which is high-temperature combustion with infrared spectroscopy. Ammonia and total sulfide, indicators of potential sediment toxicity, were analyzed by Kerouel & Aminot (1997) and SM 4500-S2-D (EPA 9030B), respectively. Ammonia analysis involved a potassium chloride extraction followed by fluorometric analysis of the extract. Total sulfide was analyzed by distillation following acidification and colorimetric analysis of the distillate. Finally, PSD analysis was performed according to

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ASTM Method D422 (ASTM, 2002), which is a combination of sieve and hydrometer analyses.

4.1.2 Metals Metals analyzed included arsenic, cadmium, chromium, copper, lead, mercury, silver, and zinc. Mercury was analyzed by cold vapor atomic absorption spectroscopy (CVAA), following EPA Method 7471B (SW-846), and all other metals were analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES) with a strong acid digestion, following EPA Method 3050B/6010D (SW8-846).

4.1.3 Organic Chemicals Organic parameters analyzed included base/neutral/acid extractable semivolatile compounds (BNAs) and polychlorinated biphenyls (PCBs). BNA samples were sonicated in 1:1 methylene chloride:acetone (3550C) and then underwent a gel permeation chromatography cleanup. BNA analysis was performed according to EPA method 8270D (SW-846), using analysis by gas chromatography/mass spectroscopy (GC/MS).

For several target analytes, using the standard methodology presented above, quantitation limits were likely to be above the SMS criteria for detection. For these analytes, KCEL included a separate Soxhlet extraction (EPA Method 3540) in an attempt to optimize the acidic and phenolic sample recoveries. Analysis for these chemicals were completed using a selected ion monitoring (SIM) scanning mode of the mass spectrometer that was optimized for early eluting acid compounds. The combination of these two steps reduced the quantitation limits for the following analytes that were analyzed with these additional steps:

• 2,4-Dimethylphenol • Benzoic Acid • Benzyl Alcohol • Dimethyl Phthalate • Hexachlorobenzene • Hexachlorobutadiene • N-Nitrosodiphenylamine • Pentachlorophenol

PCB Aroclor analysis was performed according to EPA method 8082A (SW-846), gas chromatography/electron capture detector (GC/ECD) with dual column confirmation.

4.1.4 Sediment Chemistry Quality Assurance/Quality Control All analyses were performed following guidance recommended in SCUM II (Ecology, 2017) including associated QA/QC practices. Laboratory QA/QC practices produced chemistry data of sufficient quality to pass QA1 review. Chemistry data were reviewed and flagged with data qualifiers where appropriate. A summary of QC results is provided below.

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Complete sediment chemistry analytical data, including qualifier flags, batch reports, QC data, and KCEL data quality narratives are included in Appendix B (2017 samples) and Appendix C (2018 samples).

A summary of all QC samples completed is provided in Table 4. Quality assurance marine sediment chemistry acceptance criteria are shown in Table 5. A summary narrative of QC results that did not meet laboratory control limits is provided below.

Marine sediment chemistry quality control samples. Analyte Method Spiked Duplicate/ Matrix MS SRM/LCS Surrogates Blank Blank Triplicate Spike Duplicate (MS) Ammonia Yes Yes Triplicate Yes No Yes No PSD No No Triplicate No No No No TOC Yes Yes Triplicate Yes No Yes No Total Solids Yes No Triplicate No No No No Total Volatile Yes No Triplicate No No No No Solids Total Sulfide Yes Yes Triplicate Yes No No No Mercury Yes Yes Duplicate* Yes Yes Yes No Other Metals Yes Yes Duplicate Yes No Yes No BNAs Yes Yes Duplicate Yes Yes Yes Yes PCBs Yes Yes Duplicate Yes Yes No Yes *Mercury laboratory duplicate analysis was not conducted during analysis of samples. PSD = particle size distribution; TOC = total organic carbon; BNAs = base/neutral/acid compounds; PCBs = polycyclic aromatic hydrocarbons; SRM = standard reference material; LCS = laboratory control sample

Acceptance criteria for marine sediment chemistry samples. Analyte Method Spiked Duplicate/ Matrix SRM/LCS Surrogates Blank Blank Triplicate Spike Ammonia < MDL 80 – 120% RSD < 20% 75 - 125% 80 – 120% N/A PSD N/A N/A RSD < 20% N/A N/A N/A TOC < 0.5 QL 80 - 120% RSD < 20% 75 - 125% 80 - 120% N/A Total Solids < MDL N/A RSD < 20% N/A N/A N/A Total Volatile < MDL N/A RSD < 20% N/A N/A N/A Solids Total Sulfide < 0.5 QL 80 - 120% RSD < 20% 65 - 135% N/A N/A Metals (incl. < 0.5 QL 85 – 115% RPD < 20% 75 - 125% Varies by N/A Mercury) Analyte BNAs < 0.5 QL Varies by RPD < 35% Varies by Varies by Varies by Analyte Analyte Analyte Analyte PCBs < 0.5 QL Varies by RPD < 35% Varies by N/A Varies by Analyte Analyte Analyte < MDL - Method Blank result should be less than the method detection limit; N/A = Not Applicable; < 0.5QL – Method Blank result should be less than one-half of the QL (Lower Limit of Quantitation, LLOQ), or lower in the case of BNA analyses; PSD = particle size distribution; TOC = total organic carbon; BNAs = base/neutral/acid compounds; PCBs = polycyclic aromatic hydrocarbons; SRM = standard reference material; LCS = laboratory control sample; RPD = Relative Percent Difference; RSD = Relative Standard Deviation QC results for matrix spike, SRM/LCS, and surrogates are in percent recovery of analyte.

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Conventionals All QC results for conventional parameters were within laboratory control limits with three exceptions:

• For the September 2017 sediment sampling round during the PSD analysis, the sand category’s lab triplicate (LT) relative standard deviation (RSD) exceeded the control limit. A South Plant sediment sample was used to prepare the laboratory triplicate of this workgroup and because all samples had a similar matrix consistency all South Plant sediment sample sand results were qualified “J”. • During the total sulfide analysis for both sampling events, the matrix spike (MS) recoveries were below the lower control limit. Matrix interference was suspected as the likely cause of the low recovery. Total sulfide results for all samples were qualified “JG” since they are all of a similar matrix. • During the analysis of ammonia-N for the May 2018 sampling event, several QC anomalies were noted including spike blank (SB) and laboratory control sample (LCS) recovers that were below the lower control limit. Additionally, recoveries from the matrix spike exceeded the upper control limit. Because of all the QC issues, samples were re-extracted and re-analyzed. The re-analysis indicated that matrix spike interference(s) appeared to be causing a low bias. All sample results were considered estimates and qualified with a “J” flag.

Metals All QC results for metals parameters were within laboratory control limits with two exception:

• During the total ICP metals analysis for the laboratory duplicate (LD), relative percent difference (RPD) for arsenic exceeded the control limit. Arsenic was not detected during the original sample analysis and the LD analysis yielded a result that was very slightly below the quantitation limit. The RPD was reported as 200, which is the default value in cases where either the original sample or the LD result is reported as not detected. • During both rounds of sampling/analysis, recoveries of chromium from the standard reference material (SRM) were outside of the acceptable range. Different methods for digestion and analysis (based on appropriate EPA protocols) were used by KCEL than were used to establish the values for the SRM, leading to expected, but low recoveries compared to reference levels.

No qualifiers were applied to these metals results, because results of the laboratory control sample (LCS), LCS duplicate, and the MS were within QC limits.

During the analysis of both rounds of sediment samples, a laboratory duplicate (LD) mercury sample was not included as part of the QA/QC process. However, because the mercury MS/MS duplicate (MSD) and SRM/SRM duplicate (SRMD) results were within

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laboratory control limits, acceptable precision was indicated and mercury analysis is considered to be acceptable.

Organic Chemicals All QC results for organics parameters were within laboratory control limits with the following exceptions.

During the analysis of September 2017 samples:

• Recovery of coprostanol from the spike blank (SB) was below the lower control limit. Because all other QC results including MS, MSD and SRM were within control limits, no qualifiers were applied. • Recoveries of several BNA compounds from the MS and MSD were below their respective lower control limits. These included 1,4-dicholorobenzene, 1,2- dichlorobenzene, 3-,4-methylphenol, 1,2,4-trichlorobenzene, acenaphthylene, dibenzofuran, diethyl phthalate, fluorene, di-N-butyl phthalate, pyrene, and benzo(a)pyrene. The sample selected for the MS/MSD preparation (L68433-4) was collected near the South Plant outfall. Because other QC results for most of these chemicals were within laboratory control limits, the “JG” flag was applied to these chemicals only for that one sample to denote the result was potentially low biased. • The LD RPDs for acenaphthylene, phenanthrene, and anthracene exceeded the upper control limit. The sample selected for the LD analysis was collected from a different location with a different matrix and therefore no qualifiers were applied based on these results. • During the BNA-SIM analysis, the LD RPD for benzoic acid exceeded the control limit. The sample selected for the LD analysis was collected from a different location with a different matrix. Additionally, all other QC test results for benzoic acid were within laboratory control limits and, therefore, no qualifiers were applied based on these results.

During the analysis of May 2018 samples:

• Diethyl phthalate and di-N-butyl phthalate were detected in the method blank. Di-N- butyl phthalate was not detected in any associated samples, so the results were not qualified. All sample results for diethyl phthalate were qualified “B” indicating the method blank contamination. • Recoveries of diethyl phthalate from the MS and MSD, prepared using sample L70025-1, were below the lower control limit. The diethyl phthalate result of this sample were qualified with a “JG” to indicate a potential low bias.

For organic results generated by GC/MS protocols, when chemicals were detected at concentrations less than the QL/reporting detection limit (RDL) but greater than the method detection limit (MDL), numerical results were reported and qualified “J” to denote they are considered estimates.

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4.2 Sediment Toxicity Amphipod and larval echinoderm bioassays were used to assess acute toxicity, and the juvenile polychaete bioassay was used to assess chronic toxicity of sediment samples. Bioassays were selected that would allow comparison of toxicity test results to the SMS sediment biological criteria found in SCUM II. All analyses were performed at KCEL. The bioassay tests are summarized below and detailed methodologies are available in the project’s SAP (King County, 2017). Full bioassay reports including results and QC data are available in Appendix D.

4.2.1 Sediment and Water Quality Parameters All five sediment samples were collected near the South Plant outfalls on May 30, 2018. Carr Inlet sediments were collected by KCEL staff on May 31, 2018 and used for reference sediments. Control sediments for the amphipod test were collected at the Ampelisca collection location in San Francisco Bay on June 12, 2018. Control sediments for the polychaete test were collected by KCEL staff from West Beach, Whidbey Island, WA on May 2, 2018. Samples were held at 4 ± 2 °C in the dark until tests were initiated. Holding time for test sediments ranged from nine days (juvenile polychaete test) to 23 days (amphipod test). The percentage of fines for all test sediments were within 20% (absolute) of the reference sediment percent fines (Table 6).

Bioassay sediment information including collection date, hold times, and percent fines. Hold Times (Days) % Fines Diff. From Sample Collect Ref. Locator # Date Amphipod Echinoderm Polychaete % Fines Sed. STP820NE L70025-1 5/30/2018 23 13 9 96.9 15.4 STP610MN L70025-2 5/30/2018 23 13 9 93.9 12.4 STP570MS L70025-3 5/30/2018 23 13 9 95.9 14.4 STP460S L70025-4 5/30/2018 23 13 9 98.6 17.1 STP770SE L70025-5 5/30/2018 23 13 9 95 13.5 REFSED L70174-1 5/31/2018 22 12 8 81.5 -- 5/2/2018 -- -- 37 Sand -- CONTROL* NA 6/12/2018 10 -- -- Fine-grain -- *Control sediments for the amphipod test were collected from San Francisco (with test organisms). Control sediments for the polychaete test were collected from West Beach, Whidbey Island, WA. The control for the echinoderm test is seawater only.

Natural seawater used was obtained from the NOAA Northwest Fisheries Science Center laboratory in Mukilteo, WA. The water was filtered through a 0.45 µm mini-capsule filter and salinity adjusted to 28 ppt with aerated laboratory-grade deionized water.

For all bioassay tests, samples for ammonia and sulfide were taken from water quality beakers prior to loading test organisms and at test termination. Measurements of temperature, salinity, dissolved oxygen, and pH were taken from water quality beakers

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prior to loading, before water renewal (juvenile polychaete test), and prior to test termination. For the larval echinoderm test, these measurements were also taken daily from water quality beakers. Throughout the tests, temperature and salinity measurements were taken daily in addition to temperature being taken at 15 minute intervals. Minor temperature and salinity adjustments were necessary during the tests to keep parameters within test conditions outlined by the project SAP.

4.2.2 Acute Amphipod Bioassay The organisms for the acute amphipod test, Ampelisca abdita, were collected by Brezina and Associates from San Francisco Bay, CA, on June 19, 2018. This species is used for testing of fine-grained sediments. These organisms were shipped overnight in plastic bags with a mat of sediment tubes filled with seawater and sealed. They arrived at KCEL on June 21, 2018. The tests were run according to ASTM (1993) and the Puget Sound Water Quality Authority (1995). Five replicates and a sixth beaker for water quality measurements were prepared for each sample, the negative control, and reference sample. Test, reference, and negative control beakers were prepared by placing 175 mL of test sediment in a 1 L beaker and covering it with 775 mL of filtered seawater a day prior to amphipods being added. The 20 amphipods per replicate sample were exposed to the test sediments, negative control, and reference sediment for 10 days. The beakers were checked daily for mortality and emergence of amphipods.

Additionally, two positive controls (reference toxicant) tests were conducted concurrently with the sediment test using cadmium chloride (CdCl2) and ammonium chloride (NH4Cl) as reference toxicants used in a dilution series. The tests were used to assess the relative health and sensitivity of the amphipods by comparing the results’ 96 hour LC50 values to the acceptability range of current laboratory control limits (mean LC50 ± 2 SD).

After 10 days, sediments were sieved through a 0.5 mm screen and live and dead amphipods were counted and removed. Missing amphipods were assumed to have died and decomposed prior to termination of the test. The endpoint of amphipod mortality was compared to SMS interpretive criteria.

4.2.3 Acute Larval Echinoderm Bioassay The sediment larval bioassay uses the planktonic larval form of a benthic invertebrate to test for acute toxicity to this sensitive life stage. The acute echinoderm larvae test was conducted using the sand dollar, Dendraster excentricus, according to KCEL SOP 405-v3 following protocols and procedures established by the Puget Sound Water Quality Authority (1995) and modified in SCUM II (Ecology, 2017). Test organisms were obtained from Aquatic Toxicology Support (Bremerton, WA) packed in wet towels and blue ice and held overnight at 15 ± 1°C. Five replicates and a sixth beaker for water quality measurements were prepared for each sample, the negative control, and reference samples. The test beakers and negative control samples were prepared with 18 ± 1 g of sediment in 1 L beakers with 900 mL of filtered seawater (28 ± 1 ppt); beakers were

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stirred for 10 seconds and allowed to settle for four hours. Each sample chamber received a 10 mL inoculum of the stock embryos (density of 2,500 embryos/mL).

As required in South Plant’s NPDES permit (Ecology, 2015), and detailed in the project SAP (King County, 2017), a second set of test chambers were prepared as above for side-by-side testing with a 25 µm screened tube placed in the test chamber after the four hour settling period. The screened tube, when resting in the test chamber, had a volume of approximately 173 mL. The screened tubes were inoculated with 2 mL inoculum of the same stock embryo.

Two sets of positive control tests were conducted concurrently with the sediment test using cadmium chloride and ammonium chloride as reference toxicants in a dilution series. 72 hour LC50 values were calculated using CETIS and these reference toxicant tests were used to assess the relative health and sensitivity of the larvae by comparing results to the current laboratory control limits (mean LC50 ± 2 SD).

For both methods, tests were terminated after 48-72 hrs by gently agitating the supernatant without disturbing the sediment and then decanting the liquid into a separate beaker. The liquid was agitated with a perforated plunger and 10 mL aliquots were placed in a 25 mL glass vial and preserved with 5% buffered formalin. Larval counts were made directly in the vial using an inverted compound microscope. The number of normal developed embryos, abnormal developed embryos, and total number of embryos developed from fertilized eggs were counted in 10 mL samples collected at the end of the test from all containers. Finally, the calculated endpoint of normal survivorship was compared to SMS interpretive criteria.

4.2.4 Chronic Juvenile Polychaete Bioassay Juvenile polychaete (Neanthes sp.) growth rate was used as a chronic toxicity test for South Plant sediments following methods outlined by the Puget Sound Water Quality Authority (1995). Test organisms were obtained from Aquatic Toxicology Support (Bremerton, WA). Five replicate beakers and a sixth beaker for water quality measurements were prepared for test, negative control, and reference sediments by adding 175 mL of sieved test sediment in a 1 L beaker and covering with 775 mL of filtered seawater. After a one day equilibration period five polychaetes were added to each beaker.

Two positive control tests were run concurrently with the sediment test, one using cadmium chloride and the other using ammonium chloride as reference toxicants in a dilution series. The 96 hr LC50 value was calculated for each toxicant using CETIS, and these reference toxicant tests were used to assess the relative health and sensitivity of the polychaetes by comparing results to the current laboratory control limits (mean LC50 ± 2 SD).

Tests were terminated after 20 days when the sediments were sieved through a 0.5 mm screen and live and dead polychaetes were counted and removed. Polychaetes were dried overnight at 50 °C and weighted to obtain dry weight. Pans were then placed in a 550 °C

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muffle furnace for two hours and weighed again to obtain ash-free dry weight. The primary endpoint for this test is individual growth rate reported in dry weight and ash-free dry weight; mortality was also reported. Growth rates were compared to SMS interpretive criteria.

4.2.5 Bioassay Test Quality Assurance/Quality Control Minor deviations in temperature and salinity occurred during the amphipod bioassay testing process, but those deviations were adjusted when discovered and not expected to influence test results (details available in Appendix D). No other bioassay protocol deviations occurred during the testing process.

4.3 Benthic Taxonomy EcoAnalysts were contracted to analyze the benthic taxonomy samples. Standard and accepted techniques were used to sort all organisms from each replicate sample (PSEP, 1987). Small fractions of sample material were placed in a petri dish under a 10X dissecting microscope. The petri dish was scanned systematically and all animals and associated fragments were removed using forceps. Organisms were separated out and placed in 70% ethanol according to one of the following major taxonomic groups: Annelida, Crustacea, Mollusca, and miscellaneous taxa (Echinodermata, Nemertea, Platyhelminthes, etc.). This process was repeated until all organisms were counted and identified to the lowest practical taxonomic level, typically to species. A reference collection maintained by the contractor was used to verify specimen identifications, and was used to ensure consistent identifications. If animal fragments were present, only anterior portions were counted. Identifications were performed by taxonomic experts using stereo dissecting and high- power compound microscopes. Biomass measurements were also performed in accordance with standard PSEP procedures.

A 20% aliquot of each sample was resorted to ensure 95% efficiency of all samples. Additionally, 2 of the 24 replicate samples (8.3%) were re-identified by a separate taxonomist to ensure 95% taxonomic similarity. Discrepancies between analysts were discussed and data were reconciled.

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5.0 SEDIMENT CHEMISTRY RESULTS Sediment chemistry analytical results for the 2017 South Plant monitoring event and the follow-up 2018 monitoring event are summarized below. The results are compared to the SMS criteria (values dry weight normalized for metals and polar organics, and organic carbon normalized for nonpolar organics). Complete sediment chemistry quality assurance/quality control and analytical results are available in Appendix B (2017 samples) and Appendix C (2018 samples). A summary table comparing individual sample results to SMS criteria can be found in Appendix E.

5.1 Conventionals Sediment conventional analyses included total solids, total volatile solids, PSD, TOC, ammonia nitrogen, and total sulfides. These data are summarized in Table 7.

Total solids were consistent across sites and ranged from 28.9 to 32.8% solids over both sampling events. Total solids are used to dry weight normalize chemistry results. The percentage of volatile solids ranged from 2.78 to 3.06%.

Total organic carbon concentrations were similarly consistent ranging from 19,200 to 20,800 mg/Kg dw (1.92 to 2.08%) over the two sampling events. These values are typical for deep, depositional areas of Puget Sound. TOC content for all stations was between what is considered a normal range of for sediments in Puget Sound (0.5 to 3.5%). Therefore, all chemistry results were compared to the SMS criteria, where certain chemical are OC- normalized.

Summary of sediment conventional parameters near the South Plant outfalls collected in 2017 and 2018. Minimum, maximum, and mean concentrations are only for detected values. 2017 2018 Parameter FOD Min Max Mean FOD Min Max Mean % Total Solids 8/8 28.9 32.8 31.1 5/5 30.5 32.0 31.3 % Total Volatile Solids 8/8 2.78 2.97 2.9 5/5 2.83 3.06 2.9 % Clay 8/8 42.0 52.8 44.9 5/5 33.5 36.4 35.3 % Silt 8/8 46.7 60.0 54.8 5/5 58.7 65.1 60.7 % Sand 8/8 1.4 6.8 2.2 5/5 0.9 2.2 1.5 % Gravel 1/8 0.5 0.5 0.5 1/5 0.5 0.5 0.5 % Fines 8/8 92.3 102.9 99.7 5/5 93.9 98.6 96.1 Total Organic Carbon (mg/Kg dw) 8/8 19300 20800 20100 5/5 19200 19700 19500 Total Sulfide (mg/Kg dw) 8/8 250 463 337 5/5 88.4 278 183 Ammonia Nitrogen (mg/Kg dw) 8/8 6.51 10.6 9.17 5/5 5.22 8.82 6.41 FOD = frequency of detection

Sediment near the South Plant outfalls during the two sampling events had a very high percentage of fines ranging from 92.3 to 102.9% (greater than 100% fines due to acceptable laboratory error). The fine fraction was made up of only a slightly higher percentage of silt than clay at most stations (Figure 7). This particle size distribution is

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indicative of a deep, depositional part of Puget Sound. PSD, as well as other conventional parameters were similar to previous monitoring events (King County 1997, 1999, 2001, 2002, 2012).

100% -

75% -

50% -

25% -

0% -

Figure 7. Particle size distribution of sediment samples collected near the South Plant outfalls in 2017 and 2018.

Ammonia nitrogen concentrations ranged from 5.22 to 10.6 mg/Kg dw. The maximum concentration of ammonia nitrogen was collected at station STP460S in 2017.

Total sulfide concentrations ranged from 88.4 to 463 mg/Kg dw. The maximum concentration of total sulfides was collected at station STP570MS in 2017.

5.2 Metals During the 2017 monitoring event, five of the eight metals (chromium, copper, lead, mercury, and zinc) were detected in all samples. Arsenic was detected in one and cadmium was detected in seven of eight samples. Silver was not detected in any samples. The results of the 2018 resampling event were similar to 2017, with the same five metals detected at all stations, cadmium detected in one of five samples, and arsenic and silver not detected.

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Table 8 presents the minimum, maximum, and mean concentrations for sediment metal concentrations, comparing those values to the SMS chemical criterion for each metal. All metal concentrations were below their respective criteria as were the quantitation limits of those metals not detected.

Summary of sediment metals concentrations near the South Plant outfalls collected in 2017 and 2018. Minimum, maximum, and mean concentrations are only for detected values and are reported in mg/Kg dw. 2017 2018 Parameter FOD Min Max Mean FOD Min Max Mean SQS Arsenic, Total 1/8 8.98 8.98 8.98 0/5 ------57 Cadmium, Total 7/8 0.811 0.906 0.865 1/5 0.811 0.811 0.811 5.1 Chromium, Total 8/8 37.0 42.2 39.8 5/5 38.1 41.7 40.2 260 Copper, Total 8/8 36.3 42.5 40.2 5/5 37.5 40.7 38.9 390 Lead, Total 8/8 13.3 16.3 15.1 5/5 16.5 17.3 16.8 450 Mercury, Total 8/8 0.115 0.132 0.122 5/5 0.117 0.130 0.123 0.41 Silver, Total 0/8 ------0/5 ------Zinc, Total 8/8 85.5 96.5 91.9 5/5 89.4 97.5 93.7 410 FOD = Frequency of detection -- = no detected values

5.3 Organic Chemicals Organic analytical results include semivolatile organic compounds and PCBs. All results are summarized below on either a dry weight basis (polar organics) or TOC normalized (non- polar organics) for purposes of comparison to the SQS criteria. Most PAHs, benzoic acid, benzyl alcohol, several phthalates, and some PCB Aroclors were detected in at least one sample. No phenolic compounds were detected. All quantitation limits for non-detect compounds were below the appropriate SQS when normalized to dry weight or organic carbon, as per the standard.

5.3.1 Polar Organic Chemicals Benzoic acid and benzyl alcohol were the only two polar organic compounds detected during the 2017 sampling event. Benzoic acid was detected in all samples, and concentrations ranged from 571 to 1,530 µg/Kg dw. Five of these samples had benzoic acid concentrations exceeding the combined SQS/CSL of 650 µg/Kg dw. King County also analyzed sediments at ambient and other outfall stations in the Central Basin during 2017. 47 percent (14 of 30) of the stations sampled between June and September of 2017 exceeded the SMS for benzoic acid, an occasional occurrence based upon past monitoring results (King County, 2018). Benzoic acid has anthropogenic and natural sources, and is a metabolic byproduct. Higher than normal concentrations could be an indicator of the high biological productivity noted in the Central Basin in 2017. Those stations with exceedances during the September sampling event (STP460S, STP570MS, STP610MN, STP770SE, and STP820NE) were resampled again in 2018. The 2018 benzoic acid concentrations ranged from 450 to 984 µg/Kg dw with all stations but one (STP460S) below the SQS/CSL.

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Benzyl alcohol was detected in two samples, only during the 2017 sampling event, and detected concentrations ranged from 23 to 46 µg/Kg dw, below the SQS of 57 µg/Kg dw. In 2018, none of the samples had detectable concentrations of benzyl alcohol.

The reduction of benzoic acid concentrations during the second round of sampling was not surprising. Temporary exceedances of benzoic acid have been observed occasionally during King County’s ambient sediment monitoring program (King County, 2018). Results from both events are summarized in Table 9 and illustrated in Figure 8.

Summary of polar organic concentrations near the South Plant outfalls collected in 2017 and 2018. Minimum, maximum, and mean concentrations are only for detected values and are reported in µg/Kg dry weight. 2017 2018 Parameter FOD Min Max Mean FOD Min Max Mean SQS 2,4-Dimethylphenol 0/8 ------0/5 ------29 2-Methylphenol 0/8 ------0/5 ------63 3-,4-Methylphenol 0/8 ------0/5 ------670 Benzoic acid 8/8 571 1530 767 5/5 450 984 624 650 Benzyl alcohol 2/8 23 46 35 0/5 ------57 Phenol 0/8 ------0/5 ------420 Pentachlorophenol 0/8 ------0/5 ------360 FOD = Frequency of detection -- = no detected values

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Figure 8. Summary of 2017 and 2018 South Plant sediment monitoring results highlighting exceedances of the SQS criteria for benzoic acid.

5.3.2 Nonpolar Organic Chemicals The following section provides a summary of the results of nonpolar organic chemicals analyzed in sediments collected near the South Plant outfalls. All organics in this section are presented in OC normalized concentrations.

PAHs During the 2017 sampling event, 14 of the 16 PAHs were detected in at least one sample and all were detected at concentrations below the appropriate SQS. Total low molecular weight PAHS (LPAHs) ranged from 0.70 to 13 mg/Kg OC compared to the SQS of 370 mg/Kg OC. Total high molecular weight PAHs (HPAHs) ranged from 6.1 to 64 mg/Kg OC compared to the SQS of 960 mg/Kg OC. The highest value for both of these parameters were at station STP770SE (Table 10). Fewer PAHs were detected in 2018 than were in 2017, and all concentrations were below the appropriate SQS. Concentrations of PAHs at site STP770SE were also reduced in 2018 compared to 2017 results.

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Summary of PAH concentrations near the South Plant outfalls collected in 2017 and 2018. Minimum, maximum, and mean concentrations are only for detected values and are reported in mg/Kg OC. 2017 2018 Parameter FOD Min Max Mean FOD Min Max Mean SQS Acenaphthylene 1/8 1.0 1.0 1.0 0/5 ------66 Acenaphthene 1/8 1.0 1.0 1.0 0/5 ------16 Anthracene 1/8 1.57 1.57 1.57 0/5 ------220 Fluorene 1/8 0.70 0.70 0.70 2/5 0.76 0.77 0.77 23 2-Methylnaphthalene 0/8 ------0/5 ------38 Naphthalene 0/8 ------0/5 ------99 Phenanthrene 5/8 0.72 9.20 2.6 5/5 1.21 1.95 1.45 100 Total LPAHs 5/8 0.72 13 3.5 5/5 1.22 2.7 1.77 370 Benzo(a)anthracene 8/8 0.62 5.30 1.4 5/5 0.77 1.0 0.90 110 Benzo(a)pyrene 8/8 0.67 7.05 1.7 5/5 1.0 1.21 1.1 99 Benzo(b,j,k)fluoranthene 8/8 1.63 12.0 3.42 5/5 2.67 3.08 2.82 230 Benzo(g,h,i)perylene 1/8 3.23 3.23 3.23 0/5 ------31 Chrysene 8/8 0.72 5.90 1.6 5/5 0.92 1.13 1.0 110 Dibenzo(a,h)anthracene 1/8 1.0 1.0 1.0 0/5 ------12 Fluoranthene 8/8 0.53 11.4 2.2 5/5 0.66 1.1 0.90 160 Indeno(1,2,3-c,d)pyrene 8/8 0.58 4.46 1.2 4/5 0.62 0.91 0.77 34 Pyrene 8/8 1.29 13.6 3.21 5/5 2.23 2.85 2.52 1000 Total HPAHs 8/8 6.1 64 15 5/5 8.5 11 9.9 960 FOD = Frequency of detection -- = no detected values

Phthalates Six phthalates were analyzed for in 2017 samples and only bis(2-ethylhexyl)phthalate was detected. Bis(2-ethylhexyl)phthalate was detected in two of eight samples collected in 2017 ranging from 1.2 to 2.1 mg/Kg OC compared to an SQS of 47 mg/Kg OC. During the 2018 sampling event, bis(2-ethylhexyl)phthalate was detected again at all stations ranging from 1.3 to 3.92 mg/Kg OC. Diethyl phthalate was also detected in all five 2018 samples ranging from 4.4 to 6.79 mg/Kg OC, but laboratory QC analysis indicates that blank contamination was present at concentrations more than half the wet weight sample concentrations. Even with presence of blank contamination, concentrations of diethyl phthalate were well below the SQS of 61 mg/Kg OC. A summary of all phthalate concentrations collected near the South Plant outfalls in 2017 and 2018 is available in Table 11.

Summary of phthalate concentrations near the South Plant outfalls collected in 2017 and 2018. Minimum, maximum, and mean concentrations are only for detected values and are reported in mg/Kg OC. 2017 2018 Parameter FOD Min Max Mean FOD Min Max Mean SQS Benzyl butyl phthalate 0/8 ------0/5 ------4.9 Bis(2-Ethylhexyl)phthalate 2/8 1.2 2.1 1.7 5/5 1.3 3.92 2.16 47 Di-n-butyl phthalate 0/8 ------0/5 ------220 Di-n-octyl phthalate 0/8 ------0/5 ------58

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2017 2018 Parameter FOD Min Max Mean FOD Min Max Mean SQS Diethyl phthalate 0/8 ------5/5 4.4* 6.79* 5.32* 61 Dimethyl phthalate 0/8 ------0/5 ------53 FOD = Frequency of detection -- = no detected values * = blank contamination

PCBs Three of the seven PCB Aroclors measured were detected during the 2017 sampling event (Aroclors 1242, 1254, and 1260). Total PCB Aroclors detected at seven of the eight stations ranged from 0.322 to 0.835 mg/Kg OC, which is below the SQS of 12 mg/Kg OC. During the 2018 resampling event, only Aroclor 1254 and 1260 were detected (at all five stations) and total Aroclor concentrations ranged from 0.398 to 0.518 mg/Kg OC. A summary of all PCB Aroclor concentrations collected near the South Plant outfall in 2017 and 2018 is available in Table 12.

Summary of PCB Aroclor concentrations near the South Plant outfalls collected in 2017 and 2018. Minimum, maximum, and mean concentrations are only for detected values and are reported in mg/Kg OC. 2017 2018 Parameter FOD Min Max Mean FOD Min Max Mean SQS Aroclor 1016 0/8 ------0/5 ------Aroclor 1221 0/8 ------0/5 ------Aroclor 1232 0/8 ------0/5 ------Aroclor 1242 1/8 0.228 0.228 0.228 0/5 ------Aroclor 1248 0/8 ------0/5 ------Aroclor 1254 7/8 0.159 0.354 0.232 5/5 0.216 0.287 0.241 -- Aroclor 1260 7/8 0.164 0.253 0.199 5/5 0.181 0.229 0.200 -- Total PCB Aroclors 7/8 0.322 0.835 0.463 5/5 0.398 0.518 0.442 12 FOD = Frequency of detection -- = no detected values

Miscellaneous Nonpolar Organics None of the miscellaneous organic compounds (1,2,4-Trichlorobenzene, 1,2- Dichlorobenzene, 1,4-Dichlorobenzene, hexachlorobenzene, hexachlorobutadiene, dibenzofuran, and N-nitrosodiphenylamine) were detected in any of the samples collected near the South Plant outfalls.

While not SMS chemicals of concern, total 4-nonylphenol and coprostanol were also analyzed. Coprostanol was not detected during any sampling events and total 4- nonylphenol was only detected in 2018 at station STP460S at a concentration of 26 mg/Kg OC.

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6.0 SEDIMENT TOXICITY DATA Concurrent with the second round of chemistry sampling, KCEL collected sediment samples for toxicity (bioassay) testing on May 30, 2018 at the five stations with chemical exceedances in 2017. Reference sediments were collected May 31, 2018 from Carr Inlet, WA. The results of the amphipod bioassay, larval echinoderm, and juvenile polychaete tests are summarized below. The complete laboratory report including results and quality assurance/quality control data is available in Appendix D.

6.1 Acute Amphipod Bioassay A 10-day amphipod test using Ampelisca abdita was conducted as one of two acute toxicity tests. Mean survival in test sediment ranged from 80 to 86% survival compared to 95% in negative control sediment and 86% in reference sediments. Mean avoidance (emergence) in the test ranged from 0.6 to 1.6 amphipods/beaker/day.

Using the BioStat Bioassay Data Analysis Application, no station demonstrated mortality greater than 25% on an absolute basis for statistical effect compared to the SMS Marine SQS Standard. Comparison to the SMS Interpretive Criterion is summarized in Table 13.

Comparison of amphipod bioassay results to SMS Marine Biological Criteria (SQS, CSL, and performance standards). Performance Interpretive Criteria Standards Endpoint Cont. Ref. SQS CSL MT > 25% MT – MR ≥ 30% 10-Day % MC ≤ Absolute and Locator MR ≤ 25% and MT vs. MR mortality 10% MT vs. MR SD SD (p = 0.05) (p = 0.05) CONTROL 5 PASS REFSED 14 PASS STP820NE 15 PASS NA STP610MN 14 PASS NA STP570MS 16 PASS NA STP460S 17 PASS NA STP770SE 20 PASS NA C = Control; R = Reference; T = Test; M = Mortality; SD = Significantly Different; SQS = Sediment Quality Standard; CSL = Cleanup Screening Level For the amphipod test, statistical significance is set at α = 0.05

6.2 Acute Larval Echinoderm Bioassay A 48-hour echinoderm test using Dendraster excentricus was conducted as one of two acute toxicity tests. The number of normal developed embryos, abnormal developed embryos, and the total number of embryos developed from fertilized eggs in sample replicate beakers were counted and used to calculate normal survivorship. For the standard echinoderm method, the proportion of normal survivorship was 0.82 for negative control samples and 0.75 for reference samples relative to the control. There were very low recoveries of larvae at all five stations (as low as 0.33, relative to the reference sediment)

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leading to the failure of the SMS marine SQS at all five stations and the CSL at two (Table 14).

Interference of physical factors like turbidity have been noted to affect embryo development in other King County samples. South Plant’s NPDES permit (Ecology, 2015) required concurrent echinoderm larvae tests using a modified screen tube method (King County, 2017). Under the screen tube method, normal survivorship was 0.80 for the negative control samples and 0.95 for reference samples relative to the control. Test results under the modified method ranged from 0.86 at STP460S to 0.93 at STP770SE relative to the reference sediment. All five stations passed the SMS SQS standard under the screen tube method adjustment (Table 15).

Comparison of standard echinoderm bioassay results to SMS Marine Biological Criteria (SQS, CSL, and performance standards). Standard Protocol Performance Standards Interpretative Criteria Endpoint Control Reference SQS CSL NT / NR NT / NR < 0.85 NT / NR < 0.70 Echinoderm Normal NC / I ≥ NR / NC ≥ and and and Survivorship 0.70 0.65 NT vs. NR SD NT vs. NR SD NT vs. NR SD (p = 0.10) * (p = 0.10) (p = 0.10) CONTROL 0.82 REFSED 0.75 STP820NE 0.78* FAIL PASS STP610MN 0.79* FAIL PASS STP570MS 0.64* FAIL FAIL STP460S 0.74* FAIL PASS STP770SE 0.33* FAIL FAIL C = Control; R = Reference; T = Test; N = Normal Survivorship expressed as actual counts; I = Initial count; SD = Significantly Different; SQS = Sediment Quality Standard; CSL = Cleanup Screening Level * For the larval test, statistical significance is set at = 0.10.

α Comparison of screen tube echinoderm bioassay results to SMS Marine Biological Criteria (SQS, CSL, and performance standards). Screen Tube Performance Standards Interpretative Criteria Endpoint Control Reference SQS CSL NT / NR NT / NR < 0.85 NT / NR < 0.70 Echinoderm Normal NC / I ≥ NR / NC ≥ and and and Survivorship 0.70 0.65 NT vs. NR SD NT vs. NR SD NT vs. NR SD (p = 0.10) * (p = 0.10) (p = 0.10) CONTROL 0.80 REFSED 0.95 STP820NE 0.92* PASS PASS STP610MN 0.92* PASS PASS STP570MS 0.90* PASS PASS STP460S 0.86* PASS PASS STP770SE 0.93* PASS PASS C = Control; R = Reference; T = Test; N = Normal Survivorship expressed as actual counts; I = Initial count; SD = Significantly Different; SQS = Sediment Quality Standard; CSL = Cleanup Screening Level * For the larval test, statistical significance is set at = 0.10.

α

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6.3 Chronic Juvenile Polychaete Bioassay The 20 day juvenile polychaete test using Neanthes sp. was conducted as the chronic toxicity test of South Plant sediments. Mean mortality was 0% in negative control sediments and 0% in reference sediment. Test sediment response was 0% to 4% mortality for all samples. Dry weight control mean individual growth rate (MIG) was 0.844 mg/ind/day for negative control samples and 0.845 mg/ind/day for reference sediments. Test sediment dry weight MIG ranged from 0.605 mg/ind/day at STP770SE to 0.714 mg/ind/day at STP610MN. Ash-free dry weight was 0.566 mg/ind/day for the negative control and 0.617 for reference sediments. Test sediment dry weight MIG ranged from a low of 0.505 mg/ind/day at STP770SE to 0.582 mg/ind/day at STP610MN.

All test sediment samples passed the SQS criteria using dry weight and ash-free calculations. A summary of test results are available in Table 16 and Table 17.

Comparison of dry weight Neanthes 20-day growth to SMS Marine Biological Criteria (SQS, CSL, and performance standards). Performance Sample Information Interpretative Criteria Standards Endpoint Results Control Ref. Results SQS CSL MIGT / MIGT / MC ≤ MIGT / MIGR MIGR 10% MIGR Neanthes 20- MIG MIGR / < 0.70 < 0.50 % day growth: Dry mg/ind/ and MIGC ≥ and and and Mort Weight day 0.80 MIGT vs. MIGT vs. MIGT vs. MIGC ≥ MIGR SD (p MIGR SD MIGR SD 0.72 = 0.05)* (p = 0.05) (p = 0.05) CONTROL 0.844 0 0.844 NA REFSED 0.845 0 1.00 NA PASS NA STP820NE 0.709 4 0.84* PASS NA STP610MN 0.714 0 0.84* PASS NA STP570MS 0.651 0 0.77* PASS NA STP460S 0.694 4 0.82* PASS NA STP770SE 0.605 0 0.72* PASS NA C = Control; R = Reference; T = Test; M = Mortality; SD = Significantly Different; MIG = Mean Individual Growth Rate expressed in mg/ind/day dry weight; SQS = Sediment Quality Standard; CSL = Cleanup Screening Level *For the Juvenile Polychaete tests, statistical significance is set at α = 0.05.

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Comparison of ash-free dry weight Neanthes 20-day growth to SMS Marine Biological Criteria (SQS, CSL, and performance standards). Performance Sample Information Interpretative Criteria Standards Refere Endpoint Results Control Results SQS CSL nce MIGT / MC ≤ MIGT / MIGT / MIGR MIGR 10% MIGR < 0.70 Neanthes 20- MIG MIGR / < 0.50 % day growth: Ash mg/ind/ and MIGC ≥ and and and Mort Free Dry Weight day 0.80 MIGT vs. MIGT vs. MIGT vs. MIGC ≥ MIGR SD MIGR SD MIGR SD 0.38 mg (p = 0.05)* (p = 0.05) (p = 0.05) CONTROL 0.566 0 0.566 NA REFSED 0.617 0 1.09 NA PASS NA STP820NE 0.573 4 0.93 PASS NA STP610MN 0.582 0 0.94 PASS NA STP570MS 0.542 0 0.88* PASS NA STP460S 0.564 4 0.91 PASS NA STP770SE 0.505 0 0.82 PASS NA C = Control; R = Reference; T = Test; M = Mortality; SD = Significantly Different; MIG = Mean Individual Growth Rate expressed in mg/ind/day Ash Free Dry Weight; SQS = Sediment Quality Standard; CSL = Cleanup Screening Level *For the Juvenile Polychaete tests, statistical significance is set at α = 0.05.

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7.0 BENTHIC TAXONOMY DATA A summary of benthic taxonomy results from near the South Plant outfall is presented below. This section includes a summary of benthic indices, which are used to evaluate benthic community assemblages, as well as a comparison to the benthic community at other Puget Sound stations with a long monitoring history. A complete list of all species identified and enumerated during the 2017 South Plant sediment monitoring event is included in Appendix F.

7.1 Benthic Community Indices Benthic community results (the average of the three replicate samples) from September 2017 are summarized in Table 18, along with physical sediment characteristics. Results for all replicates are provided in Appendix F. The results of all indices detailed below are based upon the organisms collected per 0.1 m2 (the area sampled by a standard van Veen grab sampler).

7.1.1 Abundance Total abundance, the number of individual organisms per sample, ranged from a low of 141 individuals (station STP610MN) to a high of 202 individuals (station STP820NE). The mean abundance was 179 individuals per sample with a standard deviation of 20.9. As expected for deep and silty sediments in Puget Sound, molluscs were the most abundant taxonomic group at every station with a mean of 121 molluscs per sample (Figure 9).

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Crustacea Mollusca Polychaeta Misc. 250 Abundance

2 200

150

100

Individuals per 0.1 m 0.1 per Individuals 50

0

STP460N STP460S STP820NE STP625NPSTP610MNSTP570MS STP625SP STP770SE Figure 9. Benthic invertebrate abundance (average of three replicates per station) by major taxonomic group at eight stations surrounding the South Plant outfall.

7.1.2 Biomass Total biomass, the combined mass (weight) of all organisms in a given sample, ranged from a minimum of 111.5 g (station STP625SP) to 265.9 g (station STP460S). The mean biomass of all stations was 182.2 g with a standard deviation of 63.0. Total biomass was driven almost exclusively by the miscellaneous taxa due to the conspicuous presence of the large sea cucumber Molpadia intermedia, which ranged in number from 2 to 13 per sample (Figure 10).

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Crustacea Mollusca Polychaeta Misc. 300 Biomass 2 250

200

150

100

50 Biomass - grams per 0.1 m 0.1 per grams - Biomass

0

STP460N STP460S STP820NE STP625NPSTP610MNSTP570MS STP625SP STP770SE Figure 10. Benthic invertebrate biomass (average of three replicates per station) by major taxonomic group at eight stations surrounding the South Plant outfall.

7.1.3 Richness Species richness, which is the number of unique taxa (generally species) per sample, ranged from a low of 31 taxa (station STP625SP) to a high of 34 taxa (station STP610MN). The mean species richness was 32 taxa per sample with a standard deviation of 1.3. At most stations polychaetes accounted for the most species, followed by crustaceans (Figure 11).

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Crustacea Mollusca Polychaeta Misc. 40 Richness

30 2

20 Taxa per 0.1 m Taxa 0.1 per 10

0

STP460N STP460S STP820NE STP625NPSTP610MNSTP570MS STP625SP STP770SE Figure 11. Benthic invertebrate richness (average of three replicates per station) by major taxonomic group at eight stations surrounding the South Plant outfall.

7.1.4 Shannon-Wiener Diversity

The Shannon-Wiener Diversity Index (H’, calculated using loge) is a measure of the relationship between taxa richness and abundance. Higher index values indicate a more diverse benthic community. H’ values ranged from a low of 2.06 (station STP770SE) to a high of 2.57 (STP610MN). The mean H’ was 2.23 with a standard deviation of 0.14.

7.1.5 Pielou’s Evenness Pielou’s Evenness Index (J), another measure of diversity, is expressed as the observed diversity in a sample as a proportion of the maximum possible diversity: a score of 0 is a sample with only one species, and a score of 1 is a sample with multiple species all occurring in the same abundance. Evenness ranged from a low of 0.59 (station STP770SE) to a high of 0.73 (station STP610MN). The average evenness of all stations was 0.64 with a standard deviation of 0.04.

7.1.6 Swartz’s Dominance The Swartz’s Dominance Index (SDI) is defined as the minimum number of species comprising 75% of the total abundance in a given sample. Low index values indicate a

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sample with little diversity, while higher values indicate a sample comprised of many species. SDI ranged from a low of 5 (average for station STP770SE) to a high of 9 (average for station STP610MN). The mean of all stations was 6 with a standard deviation of 1.2. The most abundant species in every sample was the bivalve mollusc Axinopsida serricata, which had an average abundance of 82 individuals per sample. That was followed in abundance by the bivalve Macoma calcarea or in one sample the sea cucumber Molpadia intermedia, which tied in abundance with Macoma calcarea.

Summary of conventional parameters and benthic indices of samples (average of three replicate samples) collected near the South Plant outfall.

STP820NE STP460N STP625NP STP610MN STP570MS STP625SP STP460S STP770SE Depth (m) 192 193 195 194 195 195 195 194 TOC (mg/Kg dw) 20000 20500 20200 19300 19500 20800 20700 20000 % Fines 102.2 102.9 101.4 99 98.4 102 99.5 92.3 % Clay 43.5 44.4 44.6 42.7 46.1 42 52.8 42.9 % Silt 58.7 58.5 56.8 56.3 52.3 60.0 46.7 49.4 % Sand 1.5 1.4 1.7 1.5 2.0 1.5 1.4 6.8 % Gravel ------0.5 Abundance – Total 201.7 185.0 190.0 141.0 177.3 157.3 180.0 201.0 (individuals/0.1 m2) Crustacea 27.3 25.7 27.7 15.0 19.7 15.0 24.0 25.0 Mollusca 138.3 126.7 127.0 85.3 123.3 101.7 119.7 144.0 Polychaeta 28.7 25.7 23.7 30.3 24.0 33.0 25.7 25.7 Misc. 7.3 7.0 11.7 10.3 10.3 7.7 10.7 6.3 Biomass – Total 138.63 146.81 128.26 247.83 253.88 111.50 265.86 165.08 (g/0.1 m2) Crustacea 0.25 0.27 0.60 0.40 0.20 0.17 0.20 0.35 Mollusca 0.81 0.81 2.33 8.42 0.61 0.60 1.12 0.90 Polychaeta 1.16 1.19 0.84 10.03 1.26 2.15 1.31 1.65 Misc. 136.41 144.54 124.49 228.98 251.81 108.58 263.22 162.18 Richness – Total 32.7 30.3 33.0 34.0 33.3 30.7 33.0 32.0 (unique taxa /0.1 m2) Crustacea 11.7 11.0 12.3 10.3 10.7 10.3 8.7 9.7 Mollusca 4.3 4.7 5.3 7.3 5.0 5.7 6.3 5.7 Polychaeta 14.3 12.7 12.0 13.3 14.0 12.7 13.7 14.7 Misc. 2.3 2.0 3.3 3.0 3.7 2.0 4.3 2.0 Pielou's Evenness 0.63 0.63 0.65 0.73 0.62 0.67 0.63 0.59

Shannon-Wiener (loge) 2.17 2.13 2.24 2.57 2.17 2.30 2.18 2.06 Swartz's Dominance 6.3 6.0 6.0 9.0 6.3 7.0 5.7 5.3 -- = not detected

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7.2 Comparison to Other Datasets Physical characteristics such as sediment grain size and depth are key factors in influencing what the benthic community at a given site in Puget Sound looks like (Ecology, 2018). Currently accepted reference stations for biological testing (including benthic taxonomy comparisons) such as Carr Inlet are shallow and sandy with less fines than South Plant. These stations are not appropriate for comparison to deep, depositional site like near South Plant since depth and grain size are key factors that influences benthic communities. King County is currently working with Ecology to establish benthic reference stations appropriate for comparison of silty, deep stations like the habitat surrounding the South Plant outfalls. In the event that reference stations are established, benthic invertebrate abundances near the outfall would be compared to reference station values. These results could be used in the future as a chronic biological effects test in comparison to SMS criteria.

South Plant station benthic indices of abundance, richness, evenness, and dominance were lower than regional means (Table 19) summarized in a recent report by Ecology’s Environmental Assessment Program on changes in chemical contaminants and invertebrate communities from 1989 to 2015 (Ecology, 2018). However, deep, silty stations, like those near the South Plant outfalls, tend to have lower abundances and richness than the majority of stations monitored in Puget Sound that are shallower and have a higher percentage of sand. Benthic indices near South Plant’s outfalls were within the range of the two comparable deep silty stations in the Central Basin: Point Pully and Shilshole (Table 19).

Summary of South Plant benthic indices compared to Ecology’s long-term Puget Sound benthic monitoring stations (collected from 1989 to 2015). Ecology Long- Ecology Point Ecology Term (10 Stations) Pully Station Shilshole Station South Plant 2017 min Max mean min max mean min max mean min max mean Abundance 14 4320 528 67 420 188 75 613 338 141 202 179 Richness 7 125 41 17 45 30 20 42 31 30 34 32 Pielou's Evenness 0.217 0.936 0.675 0.485 0.936 0.742 0.233 0.790 0.515 0.59 0.73 0.64 Swartz Dominance 1 33 7.9 3 16 7.8 1 10 3.6 5.3 9 6.5

While not an official reference station, the sediments collected near South Plant’s outfalls were very similar in composition to the Department of Ecology’s long-term sediment monitoring at Point Pully (station 38) in the Central Basin. That station, which is located between Seattle and Tacoma, is 200 m deep. Similar to the stations near South Plant, it has a mean value of 2.32% for TOC and a percentage of fines of 91.5%. This station also does not have a history of exceeding the SMS for chemistry with the exception of one exceedance of cadmium in 1992. From 1989 to 2015 Point Pully had an average total abundance of 188 individuals per 0.1 m2 (range: 67-420) and an average taxa richness of 30 per 0.1 m2 (range: 17-45). Molluscs, including Macoma spp. and Axinopsida serricata, tend to dominate at this site while the most conspicuous organism while sampling was the sea cucumber Molpadia intermedia. Also located in the Central Basin, Ecology’s deep (200 m) Shilshole

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station (station 29), had higher abundance than South Plant and Point Pully, but similar richness. That station had slightly lower TOC (mean = 1.8%) and percent fines (mean = 82.6%) than Point Pully and South Plant (Table 19).

The benthic community surrounding the South Plant outfalls has a similar benthic community to Point Pully where Molpadia were apparent during sample collection and molluscs were the most abundant phyla. However, notably absent from the 2017 South Plant samples was the ostracod Euphilomedes producta, which was abundant at Ecology’s Point Pully and Shilshole stations. It was discovered that taxonomists had considered ostracods meiofauna and not picked them from the 2017 South Plant samples. Original sample material was still stored and those samples will be reexamined for ostracods. Currently, however, those results have not been obtained and are not reflected in this report. King County’s data files will be updated to include these species when updated data are received. Due to the lack of ostracods, benthic indices presented here are likely biased low. Despite the lack of ostracods in the current dataset, the benthic community near the South Plant outfall indicates a moderately diverse benthic community, typical of deep silty/clayey areas in Puget Sound. The distribution of organisms in major taxonomic categories is similar at all of the benthic monitoring stations at the South Plant outfalls and an over-abundance of pollution-tolerant species was not observed.

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8.0 SUMMARY King County conducted sediment sampling and analysis near the South Plant’s marine outfalls to fulfill the sediment monitoring requirement of its South Treatment Plant NPDES permit. Sediment samples were collected from eight stations in September of 2017 and analyzed for conventionals and chemicals regulated under the SMS. Additionally, three replicate benthic taxonomy samples were collected at each of the eight stations for identification and enumeration. Based on the initial sediment chemistry results, five stations were resampled in May 2018 for repeat chemistry analysis in addition to acute and chronic toxicity testing to refute or confirm initial exceedance results.

Sample analysis followed guidance recommended in SCUM II and followed the project’s SAP with minor deviations. Quality assurance reviews were performed on all data generated from this monitoring event and showed data to be of sufficient quality to meet the data quality objectives of the project.

The initial sediment chemistry results showed that concentrations of those chemicals regulated under SMS were all well below their respective chemical criteria in all eight samples, with one exception. Benzoic acid was elevated above the combined SQS/CSL at five stations. The abnormally high benzoic acid sediment concentrations appears to have been a widespread occurrence in the Central Basin of Puget Sound based on other King County sediment monitoring results collected in 2017 (King County, 2018). The second round of sediment chemistry results indicated that concentrations of all chemicals were well below their respective chemical criteria at the five stations that initially had exceedances with the exception of one station (STP460S), which again exceeded the SQS/CSL for benzoic acid.

Three toxicity tests (two acute and one chronic) were conducted on sediments collected from the second sampling round. The biological effects criteria were met for all stations for the acute amphipod and chronic juvenile polychaete test. All five stations failed the acute echinoderm larvae test conducted using the standard method, and it was suspected that physical factors such as turbidity negatively influenced the results. However, all five stations passed the concurrently-run modified echinoderm test, which included the application of a screened tube to reduce potential influences of the physical structure/turbidity effects on the sediment results. Although benzoic acid was above the chemical criterion at station STP460S, that station passed the biological/toxicity tests indicating there were no apparent biological effects and that the station passed the SMS.

Similar to previous monitoring events, results indicate a moderately diverse benthic community, typical of deep, depositional areas in Puget Sound. There was no over- abundance of pollution-tolerant species, molluscs were the most abundant phyla, and the sea cucumber Molpadia intermedia was the most conspicuous taxa.

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Results of the combined South Plant sediment chemistry, toxicity, and benthic community analyses do not indicate a potential biological impact of effluent to the sediments surrounding the outfalls.

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9.0 REFERENCES

APHA. 2012. Standard Methods for the Examination of Water and Wastewater, 22nd Edition. American Public Health Association. Washington, D.C.

ASTM. 1993. Standard guide for conducting 10-day static sediment toxicity tests with marine and estuarine amphipods. ASTM E-1367-62. American Society for Testing and Materials, Philadelphia, PA.

ASTM. 2002. Standard Test Method for Particle-Size Analysis of Soils D422-63(2002). American Society for Testing and Materials. West Conshohocken, PA.

Ecology. 1995. Sediment Management Standards, Chapter 173-204 WAC. Washington State Department of Ecology. Olympia, WA.

Ecology. 2008. Sediment Sampling and Analysis Plan Appendix - Guidance on the Development of Sediment Sampling and Analysis Plans Meeting the Requirements of the Sediment Management Standards (Chapter 173-204 WAC) (Revised). Washington State Department of Ecology. Olympia, WA.

Ecology. 2015. National Pollutant Discharge Elimination System Waste Discharge Permit No. WA0029581. Washington State Department of Ecology. Bellevue, WA.

Ecology. 2017. Sediment Cleanup User’s Manual II: Guidance for Implementing the Cleanup Provisions of the Sediment Management Standards, Chapter 173-204 WAC. Washington State Department of Ecology. Olympia, WA.

Ecology. 2018. Sediment Quality in Puget Sound: Changes in chemical contaminants and invertebrate communities at 10 sentinel stations, 1989-2015. Publication No. 18- 03-005. Washington State Department of Ecology, Environmental Assessment Program, Olympia, WA.

EPA. 1995. Test Methods for Evaluating Solid Waste. Laboratory Manual – Physical/Chemical Methods, SW-846, 3rd Edition, Update IIB. United State Environmental Protection Agency, Office of Solid Waste and Emergency Response. Washington, D.C.

Kerouel, R. and A. Aminot. 1997. Fluorometric determination of ammonia in sea and estuarine waters by direct segmented flow analysis. Mar. Chem. 57:265-275.

King County. 1997. Water Quality Status Report for Marine Waters, 1995. King County Department of Natural Resources. Seattle, WA.

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King County. 1999. Water Quality Status Report for Marine Waters, 1997. King County Department of Natural Resources. Seattle, WA.

King County. 2001. Water Quality Status Report for Marine Waters, 1999 and 2000. King County Department of Natural Resources. Seattle, WA.

King County. 2002. Water Quality Status Report for Marine Waters, 2001. King County Department of Natural Resources. Seattle, WA.

King County. 2012. 2011 Outfall Sediment Sampling Event – King County NPDES Sediment Monitoring Program – Final Report. King County Department of Natural Resources and Parks. Seattle, WA.

King County. 2017. 2017 South Plant NPDES Outfall Sediment Sampling Event: Sampling and Analysis Plan. King County Department of Natural Resources and Parks. Seattle, WA.

King County. 2018. Letter to Shawn McKone, Permit Manager, Washington State Department of Ecology. Results of 2017 South Treatment Plant NPDES sediment monitoring event. 3/7/2018. King County Department of Natural Resources and Parks. Seattle, WA.

NOAA, University of Washington, and Washington Sea Grant. 2009. Tidal Currents of Puget Sound. Starpath Publications. Seattle, WA.

PSEP. 1987. Recommended Protocols for Sampling and Analyzing Subtidal Benthic Macroinvertebrate Assemblages in Puget Sound. Prepared for the Puget Sound Estuary Program (U.S. Environmental Protection Agency Region 10) by Tetra Tech, Inc. Seattle, WA.

Puget Sound Water Quality Authority. 1995. Recommended guidelines for conducting laboratory bioassays on Puget Sound sediments. Prepared for US EPA Region 10, Office of Puget Sound, Seattle, WA.

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Appendix A: Sample Collection Details

King County Science and Technical Support Section A-1 July 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Table A-1. South Plant sediment sample collection summary including coordinates (in NAD 83 State Plane – US feet), difference from target, depth, sample type, and grab penetration depth.

Grab I Grab II Diff. from Pen. Pen. Depth Target Sample Depth Sample Depth Station Date (m) Easting Northing (ft) Type (cm) Type (cm) 1246881 224483 6.8 Taxa 17 Taxa 17 STP460N 9/14/2017 193 1246870 224480 14.3 Taxa 17 Chem 17 1246879 224493 3.7 Chem 17 Chem 17 1246496 222181 14.9 Taxa 17 Taxa 17 9/14/2017 195 1246496 222169 14.0 Taxa 17 Chem 17 STP460S 1246497 222177 12.7 Chem 17 Chem 17 5/30/2018 193 1246507 222173 2.8 Chem/Tox 17 Chem/Tox 17 1246428 223147 18.3 Taxa 17 Taxa 17 9/14/2017 195 1246432 223142 13.9 Taxa 17 Chem 17 STP570MS 1246453 223150 10.6 Chem 17 Chem 17 5/30/2018 194 1246443 223150 8.5 Chem/Tox 17 Chem/Tox 17 1246985 223462 9.8 Taxa 17 Taxa 17 9/14/2017 194 1246980 223473 9.0 Taxa 17 -- -- STP610MN 1246991 223468 4.3 Chem 17 Chem 17 5/30/2018 194 1246995 223480 11.0 Chem/Tox 17 Chem/Tox 17 1246723 224044 15.4 Taxa 17 Taxa 17 STP625NP 9/14/2017 195 1246747 224055 12.0 Taxa 17 Chem 17 1246746 224040 16.8 Chem 17 Chem 17 1246699 222626 5.8 Taxa 17 Taxa 17 STP625SP 9/14/2017 195 1246698 222630 9.3 Taxa 17 Chem 17 1246696 222620 9.1 Chem 17 Chem 17 1247049 221943 15.3 Taxa 17 Taxa 17 9/14/2017 194 1247056 221939 7.9 Taxa 17 Chem 17 STP770SE 1247048 221932 12.1 Chem 17 Chem 17 5/30/2018 193 1247055 221926 8.2 Chem/Tox 17 Chem/Tox 17 1247430 224479 11.1 Taxa 17 Taxa 17 STP820NE 9/14/2017 192 1247435 224483 8.3 Taxa 17 Chem 17 1247429 224494 4.9 Chem 17 -- -- STP820NE 5/30/2018 194 1247436 224488 5.8 Chem/Tox 17 Chem/Tox 17 CARREF2018 5/31/2018 17.6 1186368 127596 NA Chem 17 -- --

King County Science and Technical Support Section A-2 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Appendix B: 2017 Sediment Chemistry Analytical and QA/QC Results

King County Science and Technical Support Section B-1 November 2018

Department of Natural Resources and Parks Water and Land Resources Division Environmental Laboratory 322 W. Ewing Street Seattle, WA 98119-1507 206-684-2300 Fax 206-694-2395 TTY Relay: 711

Katherine Bourbonais Phone: 206.477.7112 Fax: 206.684.9123

King County Environmental Laboratory

March 12, 2018

South Plant Outfall Sediment – Revision 2 L68418-1 through -8 Collected September 13, 2017

Sample Id. Sample Lab Sample Notes Collect Date Number STP820NE 9/14/2017 L68433-1 0 – 10 cm collection targeted STP460N 9/14/2017 L68433-2 0 – 10 cm collection targeted STP625NP 9/14/2017 L68433-3 0 – 10 cm collection targeted STP610MN 9/14/2017 L68433-4 0 – 10 cm collection targeted STP570MS 9/14/2017 L68433-5 0 – 10 cm collection targeted STP625SP 9/14/2017 L68433-6 0 – 10 cm collection targeted STP460S 9/14/2017 L68433-7 0 – 10 cm collection targeted STP770SE 9/14/2017 L68433-8 0 – 10 cm collection targeted

Enclosed please find a second revision to the laboratory data deliverables package for 8 subtidal sediment samples collected September 14, 2017 in the vicinity of the South Plant outfall. The original data package included incorrect TOC values for samples and associated QC samples, and was superseded by a revised report. However, the revised report was found to contain erroneous sample coordinates. The error has been corrected in this ‘second revision’ report.

Sample Receiving Comments Seven to eight jars of material were received for each sample. Sample jars were either frozen at -20°C or held at 4°C until analysis.

Conventionals QC Information Samples were analyzed for these conventionals parameters: ammonia-nitrogen, KCl extraction (NH3-KCl); particle size distribution (PSD), total organic carbon (TOC), total solids, total sulfide and total volatile solids (TVS). Samples were analyzed in the following analytical batches, or Work Groups (WGs): NH3-KCl WG154118 PSD WG154214 TOC WG154354 Total solids WG154189 Total sulfide WG154083 TVS WG154189 All QC results for these conventionals parameters were within laboratory control limits with these exceptions. During PSD analysis, sand category, the lab triplicate (LT) relative standard deviation (RSD) exceeded the control limit. Sample L68433-8 was used to prepare the LT. Reanalysis was not conducted because the sand category represented <10% of the overall sample mass. The LT exceedance resulted in J qualification of PSD/sand category data for all samples because they all have the same matrix consistency. During total sulfide analysis, the matrix spike (MS) recovery was below the lower control limit. A saltwater sediment sample collected from a different location for another project was used to prepare the MS. Matrix interference was suspected as the likely cause of the low recovery. Total sulfide results for all samples were qualified JG, since they are all of a similar matrix.

Metals QC Information Samples were analyzed for these metals parameters: total mercury by CVAA, total metals by ICP (arsenic, cadmium, chromium, copper, lead, silver, zinc). Samples were analyzed in the following WGs: Total mercury WG154111 Total ICP metals WG155474 All calculable QC results for metals parameters were within laboratory control limits with these exceptions. During total ICP metals analysis, the lab duplicate (LD) relative percent difference (RPD) for arsenic exceeded the control limit. No chromium was detected during the original sample analysis and the LD analysis yielded a chromium result that was very slightly below the quantitation limit (QL). The RPD was reported as 200, which is the default value in cases where either the original sample or the LD result is reported as not detected. Also, recovery of chromium from the standard reference material (SRM) was below the lower control limit. The certified SRM values were generated by a method other than that used for analysis of these sediment samples. A laboratory control sample (LCS) and LCS duplicate (LCSD) were also included in the WG, and all recoveries were acceptable. No metals results for samples in this WG were qualified on the basis of these exceedances.

Organics QC Information Samples were analyzed for these organics parameters: BNA-SMS and PCBs. Samples were analyzed in the following WGs: BNA WG155357 BNA-SIM WG155641 PCBs WG155103 All QC results for organics parameters were within laboratory control limits with these exceptions.

During BNA analysis, recovery of coprostanol from the spike blank (SB) was below the lower control limit. Recoveries of the following compounds from the MS and MS duplicate (MSD) were below the respective lower control limits: 1,4-dichlorobenzene, 1,2-dichlorobenzene, 3-,4-methylphenol, 1,2,4-trichlorobenzene, acenaphthylene, dibenzofuran, diethyl phthalate, fluorene, di-N-butyl phthalate, pyrene and benzo(a)pyrene. LD RPDs for the following compounds exceeded the upper control limit: acenaphthylene, phenanthrene and anthracene. The MS/MSD was prepared using sample L68433-4. The LD was prepared using a saltwater sediment sample collected from a different location for another project. During BNA-SIM analysis, the LD RPD for benzoic acid exceeded the control limit. The LD was prepared using a saltwater sediment sample collected from a different location for another project.

Based on these exceedances, BNA and BNA-SIM results were qualified as follows: L68433-1 L68433-2 L68433-3 L68433-4 L68433-5 L68433-6 L68433-7 L68433-8 1,2,4-Trichlorobenzene JG 1,2-Dichlorobenzene JG 1,4-Dichlorobenzene JG 3,4-Methylphenol JG Benzyl alcohol J J Acenaphthene J Acenaphthylene JG J Benzo(a)anthracene J J J J J J J Benzo(a)pyrene J JG J J J Bis-2EHP* J J Chrysene J J J J J Dibenzo(a,h)anthracene J Dibenzofuran JG Diethyl phthalate JG Di-N-butyl phthalate JG Fluoranthene J J J J J Fluorene JG J Indeno(1,2,3-cd)pyrene J J J J J J J Phenanthrene J J J Pyrene JG

Notes: Bis-2EHP = Bis(2-ethylhexyl)phthalate

This package includes sample data expressed as wet-weight and dry-weight results, laboratory Quality Control data, and copies of sample receipt and chain of custody records. Please let me know if you have any questions regarding this report.

Sincerely,

Katherine Bourbonais Laboratory Project Manager/Water Quality Planner III King County Environmental Laboratory 206.477.7112

Sample Data

King County Environmental Lab Analytical Report

Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP460N Locator: STP625NP Descrip: 820 FEET NE OF THE Descrip: 460 FEET N OF THE Descrip: JUST WEST OF THE E Sample: L68433-1 Sample: L68433-2 Sample: L68433-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 8:36 ColDate: 9/14/17 9:32 ColDate: 9/14/17 10:19 TotalSolid: 28.9 TotalSolid: 30.3 TotalSolid: 31.2 SampDepth: 192 SampDepth: 193 SampDepth: 195 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay 43.5 2.2 4.4 % 44.4 2 4 % 44.6 2 4.1 % Fines 102.2 2.2 4.4 % 102.9 2 4 % 101.4 2 4.1 % Gravel

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP460N Locator: STP625NP Descrip: 820 FEET NE OF THE Descrip: 460 FEET N OF THE Descrip: JUST WEST OF THE E Sample: L68433-1 Sample: L68433-2 Sample: L68433-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 8:36 ColDate: 9/14/17 9:32 ColDate: 9/14/17 10:19 TotalSolid: 28.9 TotalSolid: 30.3 TotalSolid: 31.2 SampDepth: 192 SampDepth: 193 SampDepth: 195 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Cadmium, Total, ICP 0.259 0.249 0.249 mg/Kg 0.252 0.247 0.247 mg/Kg 0.253 0.248 0.248 mg/Kg Chromium, Total, ICP 10.7 0.249 0.249 mg/Kg 12.3 0.247 0.247 mg/Kg 12 0.248 0.248 mg/Kg Copper, Total, ICP 10.5 0.498 0.498 mg/Kg 12.2 0.494 0.494 mg/Kg 12.4 0.496 0.496 mg/Kg Lead, Total, ICP 3.83 2.49 2.49 mg/Kg 4.22 2.47 2.47 mg/Kg 4.46 2.48 2.48 mg/Kg Silver, Total, ICP

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP460N Locator: STP625NP Descrip: 820 FEET NE OF THE Descrip: 460 FEET N OF THE Descrip: JUST WEST OF THE E Sample: L68433-1 Sample: L68433-2 Sample: L68433-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 8:36 ColDate: 9/14/17 9:32 ColDate: 9/14/17 10:19 TotalSolid: 28.9 TotalSolid: 30.3 TotalSolid: 31.2 SampDepth: 192 SampDepth: 193 SampDepth: 195 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Coprostanol

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP610MN Locator: STP570MS Locator: STP625SP Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Descrip: JUST WEST OF THE E Sample: L68433-4 Sample: L68433-5 Sample: L68433-6 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 11:25 ColDate: 9/14/17 11:59 ColDate: 9/14/17 12:51 TotalSolid: 31.2 TotalSolid: 31.3 TotalSolid: 32.6 SampDepth: 194 SampDepth: 195 SampDepth: 195 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay 42.7 1.9 3.9 % 46.1 2.1 4.2 % 42 2 4 % Fines 99 1.9 3.9 % 98.4 2.1 4.2 % 102 2 4 % Gravel

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP610MN Locator: STP570MS Locator: STP625SP Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Descrip: JUST WEST OF THE E Sample: L68433-4 Sample: L68433-5 Sample: L68433-6 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 11:25 ColDate: 9/14/17 11:59 ColDate: 9/14/17 12:51 TotalSolid: 31.2 TotalSolid: 31.3 TotalSolid: 32.6 SampDepth: 194 SampDepth: 195 SampDepth: 195 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Cadmium, Total, ICP 0.281 0.245 0.245 mg/Kg 0.277 0.247 0.247 mg/Kg

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP610MN Locator: STP570MS Locator: STP625SP Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Descrip: JUST WEST OF THE E Sample: L68433-4 Sample: L68433-5 Sample: L68433-6 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 11:25 ColDate: 9/14/17 11:59 ColDate: 9/14/17 12:51 TotalSolid: 31.2 TotalSolid: 31.3 TotalSolid: 32.6 SampDepth: 194 SampDepth: 195 SampDepth: 195 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Coprostanol

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L68433-7 Sample: L68433-8 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 13:43 ColDate: 9/14/17 14:37 TotalSolid: 30.8 TotalSolid: 32.8 SampDepth: 195 SampDepth: 194 WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay 52.8 2 4.1 % 42.9 2.1 4.3 % Fines 99.4 2 4.1 % 92.3 2.1 4.3 % Gravel

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L68433-7 Sample: L68433-8 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 13:43 ColDate: 9/14/17 14:37 TotalSolid: 30.8 TotalSolid: 32.8 SampDepth: 195 SampDepth: 194 WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Cadmium, Total, ICP 0.279 0.248 0.248 mg/Kg 0.27 0.247 0.247 mg/Kg Chromium, Total, ICP 13 0.248 0.248 mg/Kg 12.8 0.247 0.247 mg/Kg Copper, Total, ICP 13.1 0.496 0.496 mg/Kg 13.4 0.493 0.493 mg/Kg Lead, Total, ICP 5.01 2.48 2.48 mg/Kg 5.16 2.47 2.47 mg/Kg Silver, Total, ICP

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L68433-7 Sample: L68433-8 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 13:43 ColDate: 9/14/17 14:37 TotalSolid: 30.8 TotalSolid: 32.8 SampDepth: 195 SampDepth: 194 WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Coprostanol

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP460N Locator: STP625NP Descrip: 820 FEET NE OF THE Descrip: 460 FEET N OF THE Descrip: JUST WEST OF THE E Sample: L68433-1 Sample: L68433-2 Sample: L68433-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 8:36 ColDate: 9/14/17 9:32 ColDate: 9/14/17 10:19 TotalSolid: 28.9 TotalSolid: 30.3 TotalSolid: 31.2 SampDepth: 192 SampDepth: 193 SampDepth: 195 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay* 43.5 2.2 4.4 % 44.4 2 4 % 44.6 2 4.1 % Fines* 102.2 2.2 4.4 % 102.9 2 4 % 101.4 2 4.1 % Gravel*

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP460N Locator: STP625NP Descrip: 820 FEET NE OF THE Descrip: 460 FEET N OF THE Descrip: JUST WEST OF THE E Sample: L68433-1 Sample: L68433-2 Sample: L68433-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 8:36 ColDate: 9/14/17 9:32 ColDate: 9/14/17 10:19 TotalSolid: 28.9 TotalSolid: 30.3 TotalSolid: 31.2 SampDepth: 192 SampDepth: 193 SampDepth: 195 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Cadmium, Total, ICP 0.896 0.862 0.862 mg/Kg 0.832 0.815 0.815 mg/Kg 0.811 0.795 0.795 mg/Kg Chromium, Total, ICP 37 0.862 0.862 mg/Kg 40.6 0.815 0.815 mg/Kg 38.5 0.795 0.795 mg/Kg Copper, Total, ICP 36.3 1.72 1.72 mg/Kg 40.3 1.63 1.63 mg/Kg 39.7 1.59 1.59 mg/Kg Lead, Total, ICP 13.3 8.62 8.62 mg/Kg 13.9 8.15 8.15 mg/Kg 14.3 7.95 7.95 mg/Kg Silver, Total, ICP

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP460N Locator: STP625NP Descrip: 820 FEET NE OF THE Descrip: 460 FEET N OF THE Descrip: JUST WEST OF THE E Sample: L68433-1 Sample: L68433-2 Sample: L68433-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 8:36 ColDate: 9/14/17 9:32 ColDate: 9/14/17 10:19 TotalSolid: 28.9 TotalSolid: 30.3 TotalSolid: 31.2 SampDepth: 192 SampDepth: 193 SampDepth: 195 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Coprostanol

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP610MN Locator: STP570MS Locator: STP625SP Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Descrip: JUST WEST OF THE E Sample: L68433-4 Sample: L68433-5 Sample: L68433-6 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 11:25 ColDate: 9/14/17 11:59 ColDate: 9/14/17 12:51 TotalSolid: 31.2 TotalSolid: 31.3 TotalSolid: 32.6 SampDepth: 194 SampDepth: 195 SampDepth: 195 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay* 42.7 1.9 3.9 % 46.1 2.1 4.2 % 42 2 4 % Fines* 99 1.9 3.9 % 98.4 2.1 4.2 % 102 2 4 % Gravel*

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP610MN Locator: STP570MS Locator: STP625SP Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Descrip: JUST WEST OF THE E Sample: L68433-4 Sample: L68433-5 Sample: L68433-6 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 11:25 ColDate: 9/14/17 11:59 ColDate: 9/14/17 12:51 TotalSolid: 31.2 TotalSolid: 31.3 TotalSolid: 32.6 SampDepth: 194 SampDepth: 195 SampDepth: 195 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Cadmium, Total, ICP 0.901 0.785 0.785 mg/Kg 0.885 0.789 0.789 mg/Kg

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP610MN Locator: STP570MS Locator: STP625SP Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Descrip: JUST WEST OF THE E Sample: L68433-4 Sample: L68433-5 Sample: L68433-6 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 11:25 ColDate: 9/14/17 11:59 ColDate: 9/14/17 12:51 TotalSolid: 31.2 TotalSolid: 31.3 TotalSolid: 32.6 SampDepth: 194 SampDepth: 195 SampDepth: 195 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Coprostanol

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L68433-7 Sample: L68433-8 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 13:43 ColDate: 9/14/17 14:37 TotalSolid: 30.8 TotalSolid: 32.8 SampDepth: 195 SampDepth: 194 DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay* 52.8 2 4.1 % 42.9 2.1 4.3 % Fines* 99.4 2 4.1 % 92.3 2.1 4.3 % Gravel*

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L68433-7 Sample: L68433-8 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 13:43 ColDate: 9/14/17 14:37 TotalSolid: 30.8 TotalSolid: 32.8 SampDepth: 195 SampDepth: 194 DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Cadmium, Total, ICP 0.906 0.805 0.805 mg/Kg 0.823 0.753 0.753 mg/Kg Chromium, Total, ICP 42.2 0.805 0.805 mg/Kg 39 0.753 0.753 mg/Kg Copper, Total, ICP 42.5 1.61 1.61 mg/Kg 40.9 1.5 1.5 mg/Kg Lead, Total, ICP 16.3 8.05 8.05 mg/Kg 15.7 7.53 7.53 mg/Kg Silver, Total, ICP

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L68433-7 Sample: L68433-8 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 9/14/17 13:43 ColDate: 9/14/17 14:37 TotalSolid: 30.8 TotalSolid: 32.8 SampDepth: 195 SampDepth: 194 DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Coprostanol

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Project Sample Parameter Textvalue

421253-320 L68433-1 Field Personnel BK, JDD, CB, HF, JD, WEL 421253-320 L68433-1 Sediment Sampling Range 0-10 cm 421253-320 L68433-1 Sediment Type 2,0,T,3,0 421253-320 L68433-1 Tidal Condition F 421253-320 L68433-1 Total Sulfide Potential low bias: See DAF for details. 421253-320 L68433-2 Field Personnel BK, JDD, CB, HF, JD, WEL 421253-320 L68433-2 Sediment Sampling Range 0-10 cm 421253-320 L68433-2 Sediment Type 2,0,T,3,0 421253-320 L68433-2 Tidal Condition F 421253-320 L68433-2 Total Sulfide Potential low bias: See DAF for details. 421253-320 L68433-3 Field Personnel BK, JDD, CB, HF, JD, WEL 421253-320 L68433-3 Sediment Sampling Range 0-10 cm 421253-320 L68433-3 Sediment Type 2,0,T,3,1 421253-320 L68433-3 Tidal Condition F 421253-320 L68433-3 Total Sulfide Potential low bias: See DAF for details. 421253-320 L68433-4 Field Personnel BK, JDD, CB, HF, JD, WEL 421253-320 L68433-4 Sediment Sampling Range 0-10 cm 421253-320 L68433-4 Sediment Type 2,0,T,3,1 421253-320 L68433-4 Tidal Condition F 421253-320 L68433-4 Total Sulfide Potential low bias: See DAF for details. 421253-320 L68433-5 Field Personnel BK, JDD, CB, HF, JD, WEL 421253-320 L68433-5 Sediment Sampling Range 0-10 cm 421253-320 L68433-5 Sediment Type 2,0,T,3,1 421253-320 L68433-5 Tidal Condition F 421253-320 L68433-5 Total Sulfide Potential low bias: See DAF for details. 421253-320 L68433-6 Field Personnel BK, JDD, CB, HF, JD, WEL 421253-320 L68433-6 Sediment Sampling Range 0-10 cm 421253-320 L68433-6 Sediment Type 2,0,T,3,1 421253-320 L68433-6 Tidal Condition F 421253-320 L68433-6 Total Sulfide Potential low bias: See DAF for details. 421253-320 L68433-7 Field Personnel BK, JDD, CB, HF, JD, WEL 421253-320 L68433-7 Sediment Sampling Range 0-10 cm 421253-320 L68433-7 Sediment Type 2,0,T,3,1 421253-320 L68433-7 Tidal Condition S 421253-320 L68433-7 Total Sulfide Potential low bias: See DAF for details. 421253-320 L68433-8 Field Personnel BK, JDD, CB, HF, JD, WEL 421253-320 L68433-8 Sediment Sampling Range 0-10 cm 421253-320 L68433-8 Sediment Type 2,0,T,3,1 421253-320 L68433-8 Tidal Condition E 421253-320 L68433-8 Total Sulfide Potential low bias: See DAF for details.

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Quality Control Data

King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG154083 Total Sulfide

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/13/2017 9:48 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/13/2017 10:38 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/13/2017 11:12 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/13/2017 12:23 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/13/2017 12:43 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/13/2017 13:25 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/13/2017 13:50 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/13/2017 14:32 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/14/2017 8:36 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/14/2017 9:32 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/14/2017 10:19 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/14/2017 11:25 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/14/2017 11:59 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/14/2017 12:51 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/14/2017 13:43 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 9/14/2017 14:37 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG154083‐1 MB CVTOTSULFIDE‐QL OTHR SOLID 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 MB1 170918 WG154083‐2 SB CVTOTSULFIDE‐QL OTHR SOLID 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG154083‐1 WG154083‐3 LD CVTOTSULFIDE‐QL SALTWTRSED 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐1 WG154083‐4 LT CVTOTSULFIDE‐QL SALTWTRSED 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG154083‐3 L68418‐1 WG154083‐5 MS CVTOTSULFIDE‐QL SALTWTRSED 9/18/2017 9:10 9/18/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐1 WG154083‐6 MB CVTOTSULFIDE‐QL OTHR SOLID 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 MB1 170919 WG154083‐7 SB CVTOTSULFIDE‐QL OTHR SOLID 9/19/2017 9:15 9/19/2017 12:48 WG154083‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG154083‐6

Page 1 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG154118 Ammonia‐Nitrogen (NH3‐KCL)

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/13/2017 9:48 9/19/2017 8:30 9/20/2017 11:54 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/13/2017 10:38 9/19/2017 8:30 9/20/2017 10:42 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/13/2017 11:12 9/19/2017 8:30 9/20/2017 11:57 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/13/2017 12:23 9/19/2017 8:30 9/20/2017 12:18 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/13/2017 12:43 9/19/2017 8:30 9/20/2017 11:09 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/13/2017 13:25 9/19/2017 8:30 9/20/2017 12:00 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/13/2017 13:50 9/19/2017 8:30 9/20/2017 12:24 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/13/2017 14:32 9/19/2017 8:30 9/20/2017 12:02 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/14/2017 8:36 9/19/2017 8:30 9/20/2017 12:21 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/14/2017 9:32 9/19/2017 8:30 9/20/2017 11:22 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/14/2017 10:19 9/19/2017 8:30 9/20/2017 11:25 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/14/2017 11:25 9/19/2017 8:30 9/20/2017 11:28 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/14/2017 11:59 9/19/2017 8:30 9/20/2017 11:30 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/14/2017 12:51 9/19/2017 8:30 9/20/2017 11:44 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/14/2017 13:43 9/19/2017 8:30 9/20/2017 11:46 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 9/14/2017 14:37 9/19/2017 8:30 9/20/2017 11:49 WG154118‐1,‐2,‐3,‐4,‐5,‐6 WG154118‐1 MB CVNH3‐KCL OTHR SOLID 9/19/2017 8:30 9/20/2017 10:29 WG154118‐1,‐2,‐3,‐4,‐5,‐6 MB1 WG154118‐2 SB CVNH3‐KCL OTHR SOLID 9/19/2017 8:30 9/20/2017 10:32 WG154118‐1,‐2,‐3,‐4,‐5,‐6 WG154118‐1 WG154118‐3 LCS CVNH3‐KCL OTHR SOLID 9/19/2017 8:30 9/20/2017 10:34 WG154118‐1,‐2,‐3,‐4,‐5,‐6 LEVEL1 WG154118‐4 LD CVNH3‐KCL SALTWTRSED 9/19/2017 8:30 9/20/2017 10:45 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐2 WG154118‐5 LT CVNH3‐KCL SALTWTRSED 9/19/2017 8:30 9/20/2017 10:48 WG154118‐1,‐2,‐3,‐4,‐5,‐6 WG154118‐4 L68418‐2 WG154118‐6 MS CVNH3‐KCL SALTWTRSED 9/19/2017 8:30 9/20/2017 10:50 WG154118‐1,‐2,‐3,‐4,‐5,‐6 L68418‐2

Page 2 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG154189 Total Solids and TVS

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/13/2017 9:48 9/25/2017 12:55 9/26/2017 8:28 WG154189‐1,‐2,‐3 L68418‐1 421253‐310 West Point Subtidal NPDES Sediments CVTVS SALTWTRSED 9/13/2017 9:48 9/25/2017 12:55 9/26/2017 13:14 WG154189‐1,‐2,‐3 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/13/2017 10:38 9/25/2017 12:55 9/26/2017 8:29 WG154189‐1,‐2,‐3 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments CVTVS SALTWTRSED 9/13/2017 10:38 9/25/2017 12:55 9/26/2017 13:15 WG154189‐1,‐2,‐3 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/13/2017 11:12 9/25/2017 12:55 9/26/2017 8:29 WG154189‐1,‐2,‐3 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments CVTVS SALTWTRSED 9/13/2017 11:12 9/25/2017 12:55 9/26/2017 13:16 WG154189‐1,‐2,‐3 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/13/2017 12:23 9/25/2017 12:55 9/26/2017 8:29 WG154189‐1,‐2,‐3 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments CVTVS SALTWTRSED 9/13/2017 12:23 9/25/2017 12:55 9/26/2017 13:16 WG154189‐1,‐2,‐3 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/13/2017 12:43 9/25/2017 12:55 9/26/2017 8:30 WG154189‐1,‐2,‐3 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments CVTVS SALTWTRSED 9/13/2017 12:43 9/25/2017 12:55 9/26/2017 13:16 WG154189‐1,‐2,‐3 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/13/2017 13:25 9/25/2017 12:55 9/26/2017 8:30 WG154189‐1,‐2,‐3 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments CVTVS SALTWTRSED 9/13/2017 13:25 9/25/2017 12:55 9/26/2017 13:16 WG154189‐1,‐2,‐3 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/13/2017 13:50 9/25/2017 12:55 9/26/2017 8:30 WG154189‐1,‐2,‐3 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments CVTVS SALTWTRSED 9/13/2017 13:50 9/25/2017 12:55 9/26/2017 13:16 WG154189‐1,‐2,‐3 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/13/2017 14:32 9/25/2017 12:55 9/26/2017 8:30 WG154189‐1,‐2,‐3 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments CVTVS SALTWTRSED 9/13/2017 14:32 9/25/2017 12:55 9/26/2017 13:18 WG154189‐1,‐2,‐3 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/14/2017 8:36 9/25/2017 12:55 9/26/2017 8:31 WG154189‐1,‐2,‐3 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 9/14/2017 8:36 9/25/2017 12:55 9/26/2017 13:18 WG154189‐1,‐2,‐3 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/14/2017 9:32 9/25/2017 12:55 9/26/2017 8:31 WG154189‐1,‐2,‐3 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 9/14/2017 9:32 9/25/2017 12:55 9/26/2017 13:19 WG154189‐1,‐2,‐3 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/14/2017 10:19 9/25/2017 12:55 9/26/2017 8:31 WG154189‐1,‐2,‐3 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 9/14/2017 10:19 9/25/2017 12:55 9/26/2017 13:19 WG154189‐1,‐2,‐3 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/14/2017 11:25 9/25/2017 12:55 9/26/2017 8:31 WG154189‐1,‐2,‐3 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 9/14/2017 11:25 9/25/2017 12:55 9/26/2017 13:19 WG154189‐1,‐2,‐3 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/14/2017 11:59 9/25/2017 12:55 9/26/2017 8:31 WG154189‐1,‐2,‐3 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 9/14/2017 11:59 9/25/2017 12:55 9/26/2017 13:19 WG154189‐1,‐2,‐3 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/14/2017 12:51 9/25/2017 12:55 9/26/2017 8:31 WG154189‐1,‐2,‐3 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 9/14/2017 12:51 9/25/2017 12:55 9/26/2017 13:19 WG154189‐1,‐2,‐3 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/14/2017 13:43 9/25/2017 12:55 9/26/2017 8:32 WG154189‐1,‐2,‐3 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 9/14/2017 13:43 9/25/2017 12:55 9/26/2017 13:19 WG154189‐1,‐2,‐3 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 9/14/2017 14:37 9/25/2017 12:55 9/26/2017 8:32 WG154189‐1,‐2,‐3 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 9/14/2017 14:37 9/25/2017 12:55 9/26/2017 13:20 WG154189‐1,‐2,‐3 WG154189‐1 MB CVTOTS OTHR SOLID 9/25/2017 12:55 9/26/2017 8:28 WG154189‐1,‐2,‐3 MB1 170925 WG154189‐1 MB CVTVS OTHR SOLID 9/25/2017 12:55 9/26/2017 13:13 WG154189‐1,‐2,‐3 MB1 170925 WG154189‐2 LD CVTOTS SALTWTRSED 9/25/2017 12:55 9/26/2017 8:29 WG154189‐1,‐2,‐3 L68418‐2 WG154189‐2 LD CVTVS SALTWTRSED 9/25/2017 12:55 9/26/2017 13:15 WG154189‐1,‐2,‐3 L68418‐2 WG154189‐3 LT CVTOTS SALTWTRSED 9/25/2017 12:55 9/26/2017 8:29 WG154189‐1,‐2,‐3 WG154189‐2 L68418‐2 WG154189‐3 LT CVTVS SALTWTRSED 9/25/2017 12:55 9/26/2017 13:15 WG154189‐1,‐2,‐3 WG154189‐2 L68418‐2

Page 3 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG154214 PSD

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments CVPSD SALTWTRSED 9/13/2017 9:48 9/26/2017 9:25 9/28/2017 8:24 WG154214‐1,‐2 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments CVPSD SALTWTRSED 9/13/2017 10:38 9/26/2017 9:25 9/28/2017 8:24 WG154214‐1,‐2 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments CVPSD SALTWTRSED 9/13/2017 11:12 9/26/2017 9:25 9/28/2017 8:24 WG154214‐1,‐2 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments CVPSD SALTWTRSED 9/13/2017 12:23 9/26/2017 9:25 9/28/2017 8:24 WG154214‐1,‐2 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments CVPSD SALTWTRSED 9/13/2017 12:43 9/26/2017 9:25 9/28/2017 8:24 WG154214‐1,‐2 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments CVPSD SALTWTRSED 9/13/2017 13:25 9/26/2017 9:25 9/28/2017 8:24 WG154214‐1,‐2 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments CVPSD SALTWTRSED 9/13/2017 13:50 9/26/2017 9:25 9/28/2017 8:24 WG154214‐1,‐2 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments CVPSD SALTWTRSED 9/13/2017 14:32 9/26/2017 9:25 9/28/2017 8:24 WG154214‐1,‐2 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 9/14/2017 8:36 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 9/14/2017 9:32 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 9/14/2017 10:19 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 9/14/2017 11:25 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 9/14/2017 11:59 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 9/14/2017 12:51 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 9/14/2017 13:43 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 9/14/2017 14:37 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68555‐1 421093‐100 West Point EBO discharge sampling due to CVPSD SALTWTRSED 9/7/2017 12:30 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 WG154214‐1 LD CVPSD SALTWTRSED 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 L68433‐8 WG154214‐2 LT CVPSD SALTWTRSED 9/26/2017 8:30 9/27/2017 6:22 WG154214‐1,‐2 WG154214‐1 L68433‐8

Page 4 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG154354 TOC

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/13/2017 9:48 10/4/2017 14:10 10/31/2017 9:30 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/13/2017 10:38 10/4/2017 14:10 10/25/2017 10:54 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/13/2017 11:12 10/4/2017 14:10 10/31/2017 9:54 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/13/2017 12:23 10/4/2017 14:10 10/31/2017 10:18 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/13/2017 12:43 10/4/2017 14:10 10/31/2017 10:59 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/13/2017 13:25 10/4/2017 14:10 10/31/2017 11:23 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/13/2017 13:50 10/4/2017 14:10 10/31/2017 11:47 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/13/2017 14:32 10/4/2017 14:10 10/31/2017 12:44 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/14/2017 8:36 10/4/2017 14:10 11/1/2017 13:18 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/14/2017 9:32 10/4/2017 14:10 11/1/2017 13:43 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/14/2017 10:19 10/4/2017 14:10 11/1/2017 14:07 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/14/2017 11:25 10/4/2017 14:10 11/2/2017 8:39 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/14/2017 11:59 10/4/2017 14:10 11/2/2017 9:04 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/14/2017 12:51 10/4/2017 14:10 11/2/2017 9:28 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/14/2017 13:43 10/4/2017 14:10 11/2/2017 9:52 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 9/14/2017 14:37 10/4/2017 14:10 11/2/2017 10:16 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8,‐9 WG154354‐1 MB CVTOC‐QL OTHR SOLID 10/25/2017 9:13 10/25/2017 9:13 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 MB 10/04/17 WG154354‐2 SB CVTOC‐QL OTHR SOLID 10/25/2017 9:39 10/25/2017 9:39 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 WG154354‐1 WG154354‐3 LCS CVTOC‐QL OTHR SOLID 10/25/2017 10:28 10/25/2017 10:28 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 LEVEL1 WG154354‐4 LD CVTOC‐QL SALTWTRSED 10/4/2017 14:10 10/25/2017 13:30 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 L68418‐2 WG154354‐5 LT CVTOC‐QL SALTWTRSED 10/4/2017 14:10 10/25/2017 11:50 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 WG154354‐4 L68418‐2 WG154354‐6 MS CVTOC‐QL SALTWTRSED 10/4/2017 14:10 10/25/2017 12:14 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 L68418‐2 WG154354‐7 LCS CVTOC‐QL OTHR SOLID 10/31/2017 8:57 10/31/2017 8:57 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 LEVEL1 WG154354‐8 LCS CVTOC‐QL OTHR SOLID 11/1/2017 12:54 11/1/2017 12:54 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 LEVEL1 WG154354‐9 LCS CVTOC‐QL OTHR SOLID 11/2/2017 8:15 11/2/2017 8:15 WG154354‐1,‐2,‐3,‐5,‐6,‐4,‐7,‐8 LEVEL1

Page 5 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG154111 Total Mercury

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/13/2017 9:48 9/19/2017 11:15 9/20/2017 13:05 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/13/2017 10:38 9/19/2017 11:15 9/20/2017 13:07 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/13/2017 11:12 9/19/2017 11:15 9/20/2017 13:57 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/13/2017 12:23 9/19/2017 11:15 9/20/2017 13:16 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/13/2017 12:43 9/19/2017 11:15 9/20/2017 13:18 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/13/2017 13:25 9/19/2017 11:15 9/20/2017 13:24 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/13/2017 13:50 9/19/2017 11:15 9/20/2017 13:26 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/13/2017 14:32 9/19/2017 11:15 9/20/2017 13:28 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/14/2017 8:36 9/19/2017 11:15 9/20/2017 13:31 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/14/2017 9:32 9/19/2017 11:15 9/20/2017 13:33 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/14/2017 10:19 9/19/2017 11:15 9/20/2017 13:35 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/14/2017 11:25 9/19/2017 11:15 9/20/2017 13:37 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/14/2017 11:59 9/19/2017 11:15 9/20/2017 13:39 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/14/2017 12:51 9/19/2017 11:15 9/20/2017 13:41 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/14/2017 13:43 9/19/2017 11:15 9/20/2017 13:43 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 9/14/2017 14:37 9/19/2017 11:15 9/20/2017 13:50 WG154111‐1,‐2,‐3,‐4,‐5,‐6 WG154111‐1 MB MTHG‐MIDS‐QL SOLIDBLANK 9/19/2017 11:15 9/20/2017 13:01 WG154111‐1,‐2,‐3,‐4,‐5,‐6MB WG154111‐2 SB MTHG‐MIDS‐QL SOLIDBLANK 9/19/2017 11:15 9/20/2017 13:03 WG154111‐1,‐2,‐3,‐4,‐5,‐6 WG154111‐1 HG‐SMID WG154111‐3 MS MTHG‐MIDS‐QL SALTWTRSED 9/19/2017 11:15 9/20/2017 13:59 WG154111‐1,‐2,‐3,‐4,‐5,‐6 L68418‐3 HG‐SMID WG154111‐4 MSD MTHG‐MIDS‐QL SALTWTRSED 9/19/2017 11:15 9/20/2017 14:02 WG154111‐1,‐2,‐3,‐4,‐5,‐6 WG154111‐3 L68418‐3 HG‐SMID‐MSD WG154111‐5 SRM MTHG‐MIDS‐QL SALTWTRSED 9/19/2017 11:15 9/20/2017 13:53 WG154111‐1,‐2,‐3,‐4,‐5,‐6 PACS3 M‐15‐002 WG154111‐6 SRMD MTHG‐MIDS‐QL SALTWTRSED 9/19/2017 11:15 9/20/2017 13:55 WG154111‐1,‐2,‐3,‐4,‐5,‐6 WG154111‐5 PACS3 M‐15‐002

Page 6 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG155474 Total Metals by ICP

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 9/14/2017 8:36 12/15/2017 7:30 12/18/2017 11:00 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 9/14/2017 9:32 12/15/2017 7:30 12/18/2017 11:06 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 9/14/2017 10:19 12/15/2017 7:30 12/18/2017 11:17 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 9/14/2017 11:25 12/15/2017 7:30 12/18/2017 11:20 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 9/14/2017 11:59 12/15/2017 7:30 12/18/2017 11:24 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 9/14/2017 12:51 12/15/2017 7:30 12/18/2017 11:28 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 9/14/2017 13:43 12/15/2017 7:30 12/18/2017 11:32 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 9/14/2017 14:37 12/15/2017 7:30 12/18/2017 10:49 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG155474‐1 SB MTICP‐SED‐QL SOLIDBLANK 12/15/2017 7:30 12/18/2017 10:31 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG155474‐2 ICPMARINE WG155474‐2 MB MTICP‐SED‐QL SOLIDBLANK 12/15/2017 7:30 12/18/2017 10:35 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 METHOD BLANK WG155474‐3 LD MTICP‐SED‐QL SALTWTRSED 12/15/2017 7:30 12/18/2017 10:53 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐8 RPD‐SOL WG155474‐4 MS MTICP‐SED‐QL SALTWTRSED 12/15/2017 7:30 12/18/2017 10:57 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐8 ICPMARINE WG155474‐5 LCS MTICP‐SED‐QL SOIL 12/15/2017 7:30 12/18/2017 10:39 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 ERASOIL WG155474‐6 LCSD MTICP‐SED‐QL SOIL 12/15/2017 7:30 12/18/2017 10:42 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG155474‐5 ERASOIL WG155474‐7 SRM MTICP‐SED‐QL SALTWTRSED 12/15/2017 7:30 12/18/2017 10:46 WG155474‐1,‐2,‐3,‐4,‐5,‐6,‐7 PACS3

Page 7 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG155103 PCBs

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/13/2017 9:48 11/22/2017 17:00 12/5/2017 10:05 WG155103‐1,‐2,‐3,‐4,‐5 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/13/2017 10:38 11/22/2017 17:00 12/5/2017 10:23 WG155103‐1,‐2,‐3,‐4,‐5 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/13/2017 11:12 11/22/2017 17:00 12/5/2017 10:41 WG155103‐1,‐2,‐3,‐4,‐5 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/13/2017 12:23 11/22/2017 17:00 12/5/2017 11:00 WG155103‐1,‐2,‐3,‐4,‐5 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/13/2017 12:43 11/22/2017 17:00 12/5/2017 11:18 WG155103‐1,‐2,‐3,‐4,‐5 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/13/2017 13:25 11/22/2017 17:00 12/5/2017 11:36 WG155103‐1,‐2,‐3,‐4,‐5 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/13/2017 13:50 11/22/2017 17:00 12/5/2017 11:54 WG155103‐1,‐2,‐3,‐4,‐5 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/13/2017 14:32 11/22/2017 17:00 12/5/2017 12:12 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/14/2017 8:36 11/22/2017 17:00 12/5/2017 13:07 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/14/2017 9:32 11/22/2017 17:00 12/5/2017 13:25 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/14/2017 10:19 11/22/2017 17:00 12/5/2017 13:43 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/14/2017 11:25 11/22/2017 17:00 12/5/2017 14:02 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/14/2017 11:59 11/22/2017 17:00 12/5/2017 14:20 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/14/2017 12:51 11/22/2017 17:00 12/5/2017 14:38 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/14/2017 13:43 11/22/2017 17:00 12/5/2017 14:56 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 9/14/2017 14:37 11/22/2017 17:00 12/5/2017 15:14 WG155103‐1,‐2,‐3,‐4,‐5 WG155103‐1 MB ORPCB‐QL OTHR SOLID 11/22/2017 17:00 12/5/2017 8:34 WG155103‐1,‐2,‐3,‐4,‐5 MB171116 WG155103‐2 SB ORPCB‐QL OTHR SOLID 11/22/2017 17:00 12/5/2017 8:52 WG155103‐1,‐2,‐3,‐4,‐5 WG155103‐1 WG155103‐3 MS ORPCB‐QL SALTWTRSED 11/22/2017 17:00 12/5/2017 9:10 WG155103‐1,‐2,‐3,‐4,‐5 L68418‐2 WG155103‐4 MSD ORPCB‐QL SALTWTRSED 11/22/2017 17:00 12/5/2017 9:28 WG155103‐1,‐2,‐3,‐4,‐5 WG155103‐3 L68418‐2 WG155103‐5 LD ORPCB‐QL SALTWTRSED 11/22/2017 17:00 12/5/2017 9:47 WG155103‐1,‐2,‐3,‐4,‐5 L68433‐7

Page 8 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG155357 BNA‐SMS

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/13/2017 9:48 12/7/2017 6:00 12/26/2017 14:00 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/13/2017 10:38 12/7/2017 6:00 12/26/2017 14:35 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/13/2017 11:12 12/7/2017 6:00 12/26/2017 15:10 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/13/2017 12:23 12/7/2017 6:00 12/26/2017 15:46 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/13/2017 12:43 12/7/2017 6:00 12/26/2017 16:21 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/13/2017 13:25 12/7/2017 6:00 12/26/2017 16:56 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/13/2017 13:50 12/7/2017 6:00 12/26/2017 17:32 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/13/2017 14:32 12/7/2017 6:00 12/26/2017 18:07 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/14/2017 8:36 12/7/2017 6:00 12/27/2017 7:29 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/14/2017 9:32 12/7/2017 6:00 12/27/2017 8:04 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/14/2017 10:19 12/7/2017 6:00 12/27/2017 8:40 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/14/2017 11:25 12/7/2017 6:00 12/27/2017 9:15 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/14/2017 11:59 12/7/2017 6:00 12/27/2017 9:50 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/14/2017 12:51 12/7/2017 6:00 12/27/2017 10:26 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/14/2017 13:43 12/7/2017 6:00 12/27/2017 11:01 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐QL SALTWTRSED 9/14/2017 14:37 12/7/2017 6:00 12/27/2017 11:36 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG155357‐1 MB ORBNASMS‐NPDES‐QL OTHR SOLID 12/7/2017 6:00 12/26/2017 9:52 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 MB171207 WG155357‐2 SB ORBNASMS‐NPDES‐QL OTHR SOLID 12/7/2017 6:00 12/26/2017 10:28 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG155357‐1 WG155357‐3 MS ORBNASMS‐NPDES‐QL SALTWTRSED 12/7/2017 6:00 12/26/2017 11:03 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68433‐4 WG155357‐4 MSD ORBNASMS‐NPDES‐QL SALTWTRSED 12/7/2017 6:00 12/26/2017 11:38 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG155357‐3 L68433‐4 WG155357‐5 SRM ORBNASMS‐NPDES‐QL SALTWTRSED 12/7/2017 6:00 12/26/2017 12:14 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 1944 WG155357‐6 SRMD ORBNASMS‐NPDES‐QL SALTWTRSED 12/7/2017 6:00 12/26/2017 12:49 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG155357‐5 WG155357‐7 LD ORBNASMS‐NPDES‐QL SALTWTRSED 12/7/2017 6:00 12/26/2017 13:24 WG155357‐1,‐2,‐3,‐4,‐5,‐6,‐7 L68418‐2

Page 9 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment 14SEP2017

WG155641 BNA‐SMS‐NPDES‐SIM

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L68418‐1 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/13/2017 9:48 12/7/2017 6:00 12/20/2017 18:56 WG155641‐1,‐2,‐3,‐4,‐5 L68418‐2 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/13/2017 10:38 12/7/2017 6:00 12/20/2017 19:25 WG155641‐1,‐2,‐3,‐4,‐5 L68418‐3 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/13/2017 11:12 12/7/2017 6:00 12/20/2017 19:55 WG155641‐1,‐2,‐3,‐4,‐5 L68418‐4 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/13/2017 12:23 12/7/2017 6:00 12/20/2017 20:25 WG155641‐1,‐2,‐3,‐4,‐5 L68418‐5 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/13/2017 12:43 12/7/2017 6:00 12/20/2017 20:55 WG155641‐1,‐2,‐3,‐4,‐5 L68418‐6 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/13/2017 13:25 12/7/2017 6:00 12/20/2017 21:25 WG155641‐1,‐2,‐3,‐4,‐5 L68418‐7 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/13/2017 13:50 12/7/2017 6:00 12/20/2017 21:55 WG155641‐1,‐2,‐3,‐4,‐5 L68418‐8 421253‐310 West Point Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/13/2017 14:32 12/7/2017 6:00 12/20/2017 22:25 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐1 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/14/2017 8:36 12/7/2017 6:00 12/21/2017 15:59 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐2 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/14/2017 9:32 12/7/2017 6:00 12/21/2017 16:29 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐3 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/14/2017 10:19 12/7/2017 6:00 12/21/2017 16:59 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐4 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/14/2017 11:25 12/7/2017 6:00 12/21/2017 17:29 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐5 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/14/2017 11:59 12/7/2017 6:00 12/21/2017 17:59 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐6 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/14/2017 12:51 12/7/2017 6:00 12/21/2017 18:29 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐7 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/14/2017 13:43 12/7/2017 6:00 12/21/2017 18:59 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐8 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 9/14/2017 14:37 12/7/2017 6:00 12/21/2017 19:29 WG155641‐1,‐2,‐3,‐4,‐5 WG155641‐1 MB ORBNASMS‐NPDES‐SIM‐QL OTHR SOLID 12/7/2017 6:00 12/20/2017 15:26 WG155641‐1,‐2,‐3,‐4,‐5 MB171207 WG155641‐2 SB ORBNASMS‐NPDES‐SIM‐QL OTHR SOLID 12/7/2017 6:00 12/20/2017 15:56 WG155641‐1,‐2,‐3,‐4,‐5 WG155641‐1 WG155641‐3 MS ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 12/7/2017 6:00 12/20/2017 16:26 WG155641‐1,‐2,‐3,‐4,‐5 L68433‐4 WG155641‐4 MSD ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 12/7/2017 6:00 12/20/2017 16:56 WG155641‐1,‐2,‐3,‐4,‐5 WG155641‐3 L68433‐4 WG155641‐5 LD ORBNASMS‐NPDES‐SIM‐QL SALTWTRSED 12/7/2017 6:00 12/20/2017 17:26 WG155641‐1,‐2,‐3,‐4,‐5 L68418‐2

Page 10 of 10 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG154083 Total Sulfide

MB:WG154083‐1 Matrix: OTHR SOLID Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Sulfide 0.25 0.499 mg/Kg

SB:WG154083‐2 MB:WG154083‐1 Matrix: OTHR SOLID Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Total Sulfide 0.25 0.499 mg/Kg

LT:WG154083‐4 LD:WG154083‐3 L68418‐1 Matrix: SALTWTRSED Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project:421253‐310 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Total Sulfide 0.498 0.498 mg/Kg 0.564 0.734 0.735 15 0‐‐20

MS:WG154083‐5 L68418‐1 Matrix: SALTWTRSED Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project:421253‐310 Pkey:SED (Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit Total Sulfide 0.493 0.493 mg/Kg 0.564 45.22 15.5 33 * 65‐‐135

MB:WG154083‐6 Matrix: OTHR SOLID Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Sulfide 0.25 0.499 mg/Kg

SB:WG154083‐7 MB:WG154083‐6 Matrix: OTHR SOLID Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Total Sulfide 0.25 0.499 mg/Kg

Page 1 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG154118 Ammonia‐Nitrogen (NH3‐KCL)

MB:WG154118‐1 Matrix: OTHR SOLID Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Ammonia Nitrogen 0.02 0.1 mg/Kg

SB:WG154118‐2 MB:WG154118‐1 Matrix: OTHR SOLID Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Ammonia Nitrogen 0.02 0.1 mg/Kg

LCS:WG154118‐3 Matrix: OTHR SOLID Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project: Pkey:STD (Lab Control Sample) Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit Ammonia Nitrogen 0.02 0.1 mg/Kg 0.5 0.511 102 80‐‐120

LT:WG154118‐5 LD:WG154118‐4 L68418‐2 Matrix: SALTWTRSED Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project:421253‐310 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Ammonia Nitrogen 0.02 0.0989 mg/Kg 1.32 1.35 1.36 2 0‐‐20

MS:WG154118‐6 L68418‐2 Matrix: SALTWTRSED Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project:421253‐310 Pkey:SED (Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit Ammonia Nitrogen 0.019 0.0958 mg/Kg 1.32 0.4 1.7 97 75‐‐125

Page 2 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG154189 Total Solids

MB:WG154189‐1 Matrix: OTHR SOLID Listtype:CVTOTS Method:SM2540‐G Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Solids 0.005 0.01 %

MB:WG154189‐1 Matrix: OTHR SOLID Listtype:CVTVS Method:EPA 160.4 Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Volatile Solids 0.005 0.01 %

LT:WG154189‐3 LD:WG154189‐2 L68418‐2 Matrix: SALTWTRSED Listtype:CVTOTS Method:SM2540‐G Project:421253‐310 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Total Solids 0.005 0.01 % 74.5 74.6 74.8 0 0‐‐20

LT:WG154189‐3 LD:WG154189‐2 L68418‐2 Matrix: SALTWTRSED Listtype:CVTVS Method:EPA 160.4 Project:421253‐310 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Total Volatile Solids 0.005 0.01 % 1.01 1.01 1.02 1 0‐‐20

Page 3 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG154214 PSD

LT:WG154214‐2 LD:WG154214‐1 L68433‐8 Matrix: SALTWTRSED Listtype:CVPSD Method:ASTM D422 Project:421253‐320 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Gravel 0.4 4.1 % 0.5 1.6

Page 4 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG154354 TOC

MB:WG154354‐1 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Organic Carbon 243 487 mg/Kg

SB:WG154354‐2 MB:WG154354‐1 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Total Organic Carbon 243 487 mg/Kg

LCS:WG154354‐3 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Lab Control Sample) Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit Total Organic Carbon 3130 3130 mg/Kg 33510 37900 113 80‐‐120

LT:WG154354‐5 LD:WG154354‐4 L68418‐2 Matrix: SALTWTRSED Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project:421253‐310 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Total Organic Carbon 384 384 mg/Kg 1470 1810 1250 19 0‐‐20

MS:WG154354‐6 L68418‐2 Matrix: SALTWTRSED Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project:421253‐310 Pkey:SED (Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit Total Organic Carbon 479 479 mg/Kg 1470 5020 7580 122 75‐‐125

LCS:WG154354‐7 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Lab Control Sample) Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit Total Organic Carbon 3380 3380 mg/Kg 33510 33200 99 80‐‐120

LCS:WG154354‐8 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Lab Control Sample) Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit Total Organic Carbon 3530 3530 mg/Kg 33510 35000 105 80‐‐120

LCS:WG154354‐9 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Lab Control Sample) Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit Total Organic Carbon 3900 3900 mg/Kg 33510 35100 105 80‐‐120

Page 5 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG154111 Total Mercury

MB:WG154111‐1 Matrix: SOLIDBLANK Listtype:MTHG‐MIDS‐QL Method:SW846 7471B Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Mercury, Total, CVAA 0.00238 0.00476 mg/Kg

SB:WG154111‐2 MB:WG154111‐1 Matrix: SOLIDBLANK Listtype:MTHG‐MIDS‐QL Method:SW846 7471B Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Mercury, Total, CVAA 0.00238 0.00476 mg/Kg

MSD:WG154111‐4 MS:WG154111‐3 L68418‐3 Matrix: SALTWTRSED Listtype:MTHG‐MIDS‐QL Method:SW846 7471B Project:421253‐310 Pkey:SED (Matrix Spike Duplicate, Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit True Value MSD Value % Rec. Qual RPD Qual Lab Limit Mercury, Total, CVAA 0.0101 0.0101 mg/Kg 0.045 0.101 0.132 86 75‐‐125 0.101 0.136 90 3 0‐‐20

SRMD:WG154111‐6 SRM:WG154111‐5 Matrix: SALTWTRSED Listtype:MTHG‐MIDS‐QL Method:SW846 7471B Project: Pkey:SED (Std Reference Material Duplicate, Std Reference Material) Lab Parameter MDL RDL Units True Value SRM Value % Rec. Qual Lab Limit True Value SRMD Value % Rec. Qual RPD Qual Limit Mercury, Total, CVAA 0.0483 0.0483 mg/Kg 2.98 3.04 102 80‐‐120 2.98 3.07 103 1 0‐‐20

Page 6 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG155474 Total Metals by ICP

SB:WG155474‐1 MB:WG155474‐2 Matrix: SOLIDBLANK Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Silver, Total, ICP 0.238 0.476 mg/Kg

MB:WG155474‐2 Matrix: SOLIDBLANK Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Silver, Total, ICP 0.238 0.476 mg/Kg

LD:WG155474‐3 L68433‐8 Matrix: SALTWTRSED Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project:421253‐320 Pkey:SED (Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value RPD Qual Lab Limit Silver, Total, ICP 0.493 0.493 mg/Kg

MS:WG155474‐4 L68433‐8 Matrix: SALTWTRSED Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project:421253‐320 Pkey:SED (Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit Silver, Total, ICP 0.493 0.493 mg/Kg

Page 7 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

LCSD:WG155474‐6 LCS:WG155474‐5 Matrix: SOIL Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project: Pkey:STD (Lab Control Sample Duplicate, Lab Control Sample) Lab Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit True Value LCSD Value % Rec. Qual RPD Qual Limit Silver, Total, ICP 2 2 mg/Kg 31.3 29.5 94 75‐‐125 31.3 29.9 95 1 0‐‐20 Arsenic, Total, ICP 9.99 9.99 mg/Kg 145 145 100 79‐‐122 145 149 102 2 0‐‐20 Cadmium, Total, ICP 0.999 0.999 mg/Kg 87.6 85.3 97 80‐‐120 87.6 92 105 8 0‐‐20 Chromium, Total, ICP 0.999 0.999 mg/Kg 143 133 93 79‐‐120 143 149 104 12 0‐‐20 Copper, Total, ICP 2 2 mg/Kg 173 172 99 80‐‐120 173 188 108 9 0‐‐20 Lead, Total, ICP 9.99 9.99 mg/Kg 146 137 94 80‐‐120 146 145 99 6 0‐‐20 Zinc, Total, ICP 0.999 0.999 mg/Kg 194 187 96 80‐‐120 194 201 104 7 0‐‐20

SRM:WG155474‐7 Matrix: SALTWTRSED Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project: Pkey:SED (Std Reference Material) Parameter MDL RDL Units True Value SRM Value % Rec. Qual Lab Limit Arsenic, Total, ICP 10 10 mg/Kg 30.3 26.9 89 80‐‐120 Cadmium, Total, ICP 1 1 mg/Kg 2.23 2.58 116 80‐‐120 Chromium, Total, ICP 1 1 mg/Kg 90.6 45.3 50 * 80‐‐120 Copper, Total, ICP 2 2 mg/Kg 326 306 94 80‐‐120 Lead, Total, ICP 10 10 mg/Kg 188 163 87 80‐‐120 Zinc, Total, ICP 1 1 mg/Kg 376 351 93 80‐‐120

Page 8 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG155103 PCBs

MB:WG155103‐1 Matrix: OTHR SOLID Listtype:ORPCB‐QL Method:SW846 3550B*SW846 8082A Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Aroclor 1016 0.417 0.833 ug/Kg

SB:WG155103‐2 MB:WG155103‐1 Matrix: OTHR SOLID Listtype:ORPCB‐QL Method:SW846 3550B*SW846 8082A Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Aroclor 1242 0.417 0.833 ug/Kg

MSD:WG155103‐4 MS:WG155103‐3 L68418‐2 Matrix: SALTWTRSED Listtype:ORPCB‐QL Method:SW846 3550B*SW846 8082A Project:421253‐310 Pkey:SED (Matrix Spike Duplicate, Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit True Value MSD Value % Rec. Qual RPD Qual Lab Limit Aroclor 1242 0.833 0.833 ug/Kg 4.33 66.7 51.6 71 51‐‐100 66.7 53 73 3 0‐‐35 Aroclor 1260 0.833 0.833 ug/Kg 2.48 66.7 61 88 35‐‐108 66.7 61.7 89 1 0‐‐35

LD:WG155103‐5 L68433‐7 Matrix: SALTWTRSED Listtype:ORPCB‐QL Method:SW846 3550B*SW846 8082A Project:421253‐320 Pkey:SED (Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value RPD Qual Lab Limit Aroclor 1016 0.833 0.833 ug/Kg

Page 9 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

2,4,5,6‐ Tetra chloro m‐ Decachloro Surrogate: xylene biphenyl (Lab Limits) 22‐‐113 51‐‐115 L68418‐17380 L68418‐27084 L68418‐36877 L68418‐47088 L68418‐56987 L68418‐6 78 104 L68418‐76782 L68418‐87078 L68433‐18791 L68433‐27178 L68433‐36874 L68433‐47380 L68433‐57379 L68433‐67074 L68433‐78184 L68433‐87192 WG155103‐17898 WG155103‐26990 WG155103‐36675 WG155103‐46977 WG155103‐58099

Page 10 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG155357 BNASMS

MB:WG155357‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Phenol 17 33.3 ug/Kg

Page 11 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

SB:WG155357‐2 MB:WG155357‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Phenol 17 33.3 ug/Kg

Page 12 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

MSD:WG155357‐4 MS:WG155357‐3 L68433‐4 Matrix: SALTWTRSED Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project:421253‐320 Pkey:SED (Matrix Spike Duplicate, Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit True Value MSD Value % Rec. Qual RPD Qual Lab Limit Phenol 17 33.3 ug/Kg

Page 13 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

SRMD:WG155357‐6 SRM:WG155357‐5 Matrix: SALTWTRSED Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project: Pkey:SED (Std Reference Material Duplicate, Std Reference Material) Lab Parameter MDL RDL Units True Value SRM Value % Rec. Qual Lab Limit True Value SRMD Value % Rec. Qual RPD Qual Limit Phenanthrene 170 333 ug/Kg 5200 2820 54 48‐‐112 5200 2720 52 4 0‐‐35 Fluoranthene 170 333 ug/Kg 8800 4630 53 42‐‐127 8800 4430 50 4 0‐‐35 Pyrene 170 333 ug/Kg 9570 4260 45 39‐‐119 9570 4060 42 5 0‐‐35 Benzo(a)anthracene 170 333 ug/Kg 4660 2040 44 41‐‐122 4660 1970 42 4 0‐‐35 Chrysene 170 333 ug/Kg 4800 2910 61 50‐‐144 4800 2780 58 4 0‐‐35 Benzo(b,j,k)fluoranthene 250 500 ug/Kg 8150 5100 63 40‐‐122 8150 4830 59 6 0‐‐35 Benzo(a)pyrene 170 333 ug/Kg 4240 1680 40 31‐‐117 4240 1560 37 8 0‐‐35 Indeno(1,2,3‐Cd)Pyrene 170 333 ug/Kg 2740 1370 50 36‐‐127 2740 1360 50 1 0‐‐35 Dibenzo(a,h)anthracene 170 333 ug/Kg 419 440 105 41‐‐200 419 413 99 6 0‐‐35 Benzo(g,h,i)perylene 170 333 ug/Kg 2800 940 34 25‐‐133 2800 828 30 13 0‐‐35

Page 14 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

LD:WG155357‐7 L68418‐2 Matrix: SALTWTRSED Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project:421253‐310 Pkey:SED (Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value RPD Qual Lab Limit Phenol 17 33.3 ug/Kg

Page 15 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

2,4,6‐ Tribromo 2‐Fluoro d5‐Nitro Surrogate: phenol phenol benzene d5‐Phenol (Lab Limits) 20‐‐150 20‐‐136 22‐‐126 20‐‐142 L68418‐1 81444851 L68418‐2 75353738 L68418‐3 91434650 L68418‐4 95465052 L68418‐5 70384042 L68418‐6 90444650 L68418‐7 83444750 L68418‐8 78384242 L68433‐1 78283036 L68433‐2 50232425 L68433‐3 74353740 L68433‐4 74343739 L68433‐5 74373941 L68433‐6 73343739 L68433‐7 66323435 L68433‐8 79465054 WG155357‐1 53465355 WG155357‐2 69434648 WG155357‐3 67313336 WG155357‐4 69333436 WG155357‐5 59293641 WG155357‐6 46233536 WG155357‐7 76363941

Page 16 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

Workgroup: WG155641 BNASMS‐NPDES‐SIM

MB:WG155641‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐SIM‐QL Method:8270D‐SIM Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Benzyl Alcohol 6.7 16.7 ug/Kg

SB:WG155641‐2 MB:WG155641‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐SIM‐QL Method:8270D‐SIM Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Benzyl Alcohol 6.7 16.7 ug/Kg

MSD:WG155641‐4 MS:WG155641‐3 L68433‐4 Matrix: SALTWTRSED Listtype:ORBNASMS‐NPDES‐SIM‐QL Method:8270D‐SIM Project:421253‐320 Pkey:SED (Matrix Spike Duplicate, Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit True Value MSD Value % Rec. Qual RPD Qual Lab Limit Benzyl Alcohol 6.7 16.7 ug/Kg

Page 17 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment 14SEP2017

LD:WG155641‐5 L68418‐2 Matrix: SALTWTRSED Listtype:ORBNASMS‐NPDES‐SIM‐QL Method:8270D‐SIM Project:421253‐310 Pkey:SED (Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value RPD Qual Lab Limit Benzyl Alcohol 6.7 16.7 ug/Kg 9.6

2‐Fluoro d14‐Ter d4‐2‐Chloro Surrogate: biphenyl phenyl phenol (Lab Limits) 30‐‐150 30‐‐150 30‐‐150 L68418‐1 679073 L68418‐2 498754 L68418‐3 598957 L68418‐4 508354 L68418‐5 548459 L68418‐6 578460 L68418‐7 618766 L68418‐8 558557 L68433‐1 487841 L68433‐2 386138 L68433‐3 517553 L68433‐4 517851 L68433‐5 517754 L68433‐6 487449 L68433‐7 467451 L68433‐8 698172 WG155641‐1 54 113 57 WG155641‐2 688866 WG155641‐3 588351 WG155641‐4 568452 WG155641‐5 667952

======If the following parameters are reported, values in the RPD column are actually Absolute Differences pH, Field Salinity, Field Sample Depth Sample Temperature, Field

Page 18 of 18

Sample Receipt and Chain of Custody Records

2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Appendix C: 2018 Sediment Chemistry Analytical and QA/QC Results

King County Science and Technical Support Section C-1 November 2018

Department of Natural Resources and Parks Water and Land Resources Division Environmental Laboratory 322 W. Ewing Street Seattle, WA 98119-1507 206-684-2300 Fax 206-694-2395 TTY Relay: 711

Katherine Bourbonais Phone: 206.477.7112 Fax: 206.684.9123

King County Environmental Laboratory

July 26, 2018

South Plant Outfall Sediment - Resampling L70025-1 through -5 Collected May 30, 2018

Sample Id. Sample Lab Sample Notes Collect Date Number STP820NE 5/30/2018 L70025-1 0 – 10 cm collection targeted STP610MN 5/30/2018 L70025-1 0 – 10 cm collection targeted STP570MS 5/30/2018 L70025-1 0 – 10 cm collection targeted STP460S 5/30/2018 L70025-1 0 – 10 cm collection targeted STP770SE 5/30/2018 L70025-1 0 – 10 cm collection targeted

Enclosed please find a laboratory data deliverables package for 5 subtidal sediment samples collected May 30, 2018 in the vicinity of the South Treatment Plant outfall. These locations were resampled due to Sediment Management Standards (MSM) exceedances in previously collected samples.

Sample Collection and Receiving Comments Two casts were required to collect enough sample material to complete all requested analyses. All grabs had sea cucumbers, sea biscuits and some worms. STP460S had noticeably more organisms than the other stations. Consistency of the sample matrix was described as “sort of sticky” (L70025-1 and -5) to “very sticky” (L70025-2 through -4). Eleven to twelve jars of material were received for each sample. Sample jars were either frozen at -20°C or held at 4°C until analysis.

Conventionals QC Information Samples were analyzed for these conventionals parameters: ammonia-nitrogen, KCl extraction (NH3-KCl); particle size distribution (PSD), total organic carbon (TOC), total solids, total sulfide and total volatile solids (TVS).

Samples were analyzed in the following analytical batches, or Work Groups (WGs): NH3-KCl WG158652 PSD WG158362 TOC WG158222 Total solids WG158029 Total sulfide WG158247 TVS WG158029 All QC results for these conventionals parameters were within laboratory control limits with these exceptions. During total sulfide analysis, the matrix spike (MS) recovery was below the lower control limit, which was due to the elevated total sulfide concentration in the sample selected for MS preparation. Sample L70025-2 was used for MS preparation. The matrix interference described above was suspected as the likely cause of the low recovery. Samples were diluted and re-analyzed. Total sulfide results for all samples were qualified JG, since they are all of a similar matrix, and results could potentially be biased low. During NH3-KCl analysis, several anomalies were noted. Spike blank (SB) and Lab Control Sample (LCS) recoveries were below the lower control limit. Recovery from the matrix spike (MS), prepared using sample L70025-1, exceeded the upper control limit. Samples had been re-extracted and re-analyzed due to QC anomalies noted during the first analysis. Matrix interference(s) appear to be causing a low bias. All sample results and the method blank (MB) result are qualified J, TA to indicate they should be considered estimated, and additional text information is available.

Metals QC Information Samples were analyzed for these metals parameters: total mercury by CVAA, total metals by ICP (arsenic, cadmium, chromium, copper, lead, silver, zinc). Samples were analyzed in the following WGs: Total mercury WG158100 Total ICP metals WG158388 All calculable QC results for metals parameters were within laboratory control limits with these exceptions. During total ICP metals analysis, recovery of chromium from the standard reference material (SRM, PACS3) was below the lower control limit. The certified SRM values were generated by a method other than that used for analysis of these sediment samples. A laboratory control sample (LCS) and LCS duplicate (LCSD) were also included in the WG, and all recoveries were acceptable. Therefore, chromium results for the samples in this WG were not qualified.

Organics QC Information Samples were analyzed for these organics parameters: BNA, BNA-SIM and PCBs. Samples were analyzed in the following WGs: BNA WG158323 BNA-SIM WG158607 PCBs WG158325 All QC results for organics parameters were within laboratory control limits with these exceptions.

During BNA analysis, diethyl phthalate and di-N-butyl phthalate were detected in the method blank (MB). Results for both MB detections were qualified B on this basis. Di-N-butyl phthalate was not detected in any of the associated samples, so sample results for this compound were not qualified. All sample results for diethyl phthalate were qualified B.

Recoveries of diethyl phthalate from the matrix spike (MS) and MS duplicate (MSD) were below the lower control limit. Sample L70025-1 was used for MS/MSD preparation. The diethyl phthalate result for this sample was qualified JG, to indicate potential low bias. A number of compounds were detected in samples at concentrations between the detection limit and the quantitation limit (QL). Numerical results have been reported for these compounds but all such results are qualified J to indicate the reported numerical values should be considered estimates.

Based on these occurrences, BNA results were qualified as follows: L70025-1 L70025-2 L70025-3 L70025-4 L70025-5 Benzoic acid J J Benzo(a)anthracene J J J J J Benzo(a)pyrene J J J Bis-2EHP* J J J J Chrysene J J J Diethyl phthalate J J Fluoranthene J J J J Fluorene J J Indeno(1,2,3-cd)pyrene J J J J Total 4-nonylphenol J

Notes: Bis-2EHP = Bis(2-ethylhexyl)phthalate

This package includes sample data expressed as wet-weight and dry-weight results, laboratory Quality Control data, and copies of sample receipt and chain of custody records. Please let me know if you have any questions regarding this report.

Sincerely,

Katherine Bourbonais Laboratory Project Manager/Water Quality Planner III King County Environmental Laboratory 206.477.7112

Sample Data

King County Environmental Lab Analytical Report

Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP610MN Locator: STP570MS Descrip: 820 FEET NE OF THE Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Sample: L70025-1 Sample: L70025-2 Sample: L70025-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 8:06 ColDate: 5/30/18 8:46 ColDate: 5/30/18 9:16 TotalSolid: 30.5 TotalSolid: 31.7 TotalSolid: 31.1 SampDepth: 194 SampDepth: 194 SampDepth: 194 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay 36.4 2 4 % 35.2 2 3.9 % 36 2 4 % Fines 96.9 2 4 % 93.9 2 3.9 % 95.9 2 4 % Gravel

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP610MN Locator: STP570MS Descrip: 820 FEET NE OF THE Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Sample: L70025-1 Sample: L70025-2 Sample: L70025-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 8:06 ColDate: 5/30/18 8:46 ColDate: 5/30/18 9:16 TotalSolid: 30.5 TotalSolid: 31.7 TotalSolid: 31.1 SampDepth: 194 SampDepth: 194 SampDepth: 194 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Copper, Total, ICP 11.9 0.504 0.504 mg/Kg 12.9 0.499 0.499 mg/Kg 11.9 0.504 0.504 mg/Kg Lead, Total, ICP 5.19 2.52 2.52 mg/Kg 5.47 2.49 2.49 mg/Kg 5.12 2.52 2.52 mg/Kg Silver, Total, ICP

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP610MN Locator: STP570MS Descrip: 820 FEET NE OF THE Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Sample: L70025-1 Sample: L70025-2 Sample: L70025-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 8:06 ColDate: 5/30/18 8:46 ColDate: 5/30/18 9:16 TotalSolid: 30.5 TotalSolid: 31.7 TotalSolid: 31.1 SampDepth: 194 SampDepth: 194 SampDepth: 194 WET Weight Basis WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Dibenzofuran

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L70025-4 Sample: L70025-5 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 9:42 ColDate: 5/30/18 10:17 TotalSolid: 32 TotalSolid: 31.4 SampDepth: 193 SampDepth: 193 WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay 33.5 2 3.9 % 35.6 2 4 % Fines 98.6 2 3.9 % 95 2 4 % Gravel

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L70025-4 Sample: L70025-5 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 9:42 ColDate: 5/30/18 10:17 TotalSolid: 32 TotalSolid: 31.4 SampDepth: 193 SampDepth: 193 WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Copper, Total, ICP 12 0.507 0.507 mg/Kg 12.3 0.504 0.504 mg/Kg Lead, Total, ICP 5.3 2.54 2.54 mg/Kg 5.28 2.52 2.52 mg/Kg Silver, Total, ICP

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L70025-4 Sample: L70025-5 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 9:42 ColDate: 5/30/18 10:17 TotalSolid: 32 TotalSolid: 31.4 SampDepth: 193 SampDepth: 193 WET Weight Basis WET Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Dibenzofuran

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP610MN Locator: STP570MS Descrip: 820 FEET NE OF THE Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Sample: L70025-1 Sample: L70025-2 Sample: L70025-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 8:06 ColDate: 5/30/18 8:46 ColDate: 5/30/18 9:16 TotalSolid: 30.5 TotalSolid: 31.7 TotalSolid: 31.1 SampDepth: 194 SampDepth: 194 SampDepth: 194 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay* 36.4 2 4 % 35.2 2 3.9 % 36 2 4 % Fines* 96.9 2 4 % 93.9 2 3.9 % 95.9 2 4 % Gravel*

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP610MN Locator: STP570MS Descrip: 820 FEET NE OF THE Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Sample: L70025-1 Sample: L70025-2 Sample: L70025-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 8:06 ColDate: 5/30/18 8:46 ColDate: 5/30/18 9:16 TotalSolid: 30.5 TotalSolid: 31.7 TotalSolid: 31.1 SampDepth: 194 SampDepth: 194 SampDepth: 194 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Copper, Total, ICP 39 1.65 1.65 mg/Kg 40.7 1.57 1.57 mg/Kg 38.3 1.62 1.62 mg/Kg Lead, Total, ICP 17 8.26 8.26 mg/Kg 17.3 7.85 7.85 mg/Kg 16.5 8.1 8.1 mg/Kg Silver, Total, ICP

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Project: 421253-320 Project: 421253-320 Project: 421253-320 Locator: STP820NE Locator: STP610MN Locator: STP570MS Descrip: 820 FEET NE OF THE Descrip: 610 FEET SOUTH OF Descrip: 570 FEET NORTH OF Sample: L70025-1 Sample: L70025-2 Sample: L70025-3 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 8:06 ColDate: 5/30/18 8:46 ColDate: 5/30/18 9:16 TotalSolid: 30.5 TotalSolid: 31.7 TotalSolid: 31.1 SampDepth: 194 SampDepth: 194 SampDepth: 194 DRY Weight Basis DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Value Qual MDL RDL Units Dibenzofuran

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L70025-4 Sample: L70025-5 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 9:42 ColDate: 5/30/18 10:17 TotalSolid: 32 TotalSolid: 31.4 SampDepth: 193 SampDepth: 193 DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units CV ASTM D422 Clay* 33.5 2 3.9 % 35.6 2 4 % Fines* 98.6 2 3.9 % 95 2 4 % Gravel*

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L70025-4 Sample: L70025-5 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 9:42 ColDate: 5/30/18 10:17 TotalSolid: 32 TotalSolid: 31.4 SampDepth: 193 SampDepth: 193 DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Copper, Total, ICP 37.5 1.58 1.58 mg/Kg 39.2 1.61 1.61 mg/Kg Lead, Total, ICP 16.6 7.94 7.94 mg/Kg 16.8 8.03 8.03 mg/Kg Silver, Total, ICP

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Project: 421253-320 Project: 421253-320 Locator: STP460S Locator: STP770SE Descrip: 460 FEET SOUTH OF Descrip: 770 FEET SE OF THE Sample: L70025-4 Sample: L70025-5 Matrix: SF SALTWTRSED Matrix: SF SALTWTRSED ColDate: 5/30/18 9:42 ColDate: 5/30/18 10:17 TotalSolid: 32 TotalSolid: 31.4 SampDepth: 193 SampDepth: 193 DRY Weight Basis DRY Weight Basis

Parameters Value Qual MDL RDL Units Value Qual MDL RDL Units Dibenzofuran

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Project Sample Parameter Textvalue

421253-320 L70025-1 Ammonia Nitrogen Estimated Value: See DAF for details. 421253-320 L70025-1 Field Personnel HF, BK, CB, SH, JDD 421253-320 L70025-1 Sediment Sampling Range 0-10 cm 421253-320 L70025-1 Sediment Type 23N31. ; 86% Fines 421253-320 L70025-1 Tidal Condition E 421253-320 L70025-1 Total Sulfide Potential low bias: See DAF for details. 421253-320 L70025-2 Ammonia Nitrogen Estimated Value: See DAF for details. 421253-320 L70025-2 Field Personnel HF, BK, CB, SH, JDD 421253-320 L70025-2 Sediment Sampling Range 0-10 cm 421253-320 L70025-2 Sediment Type 23N31. ; 86% Fines 421253-320 L70025-2 Tidal Condition E 421253-320 L70025-2 Total Sulfide Potential low bias: See DAF for details. 421253-320 L70025-3 Ammonia Nitrogen Estimated Value: See DAF for details. 421253-320 L70025-3 Field Personnel HF, BK, CB, SH, JDD 421253-320 L70025-3 Sediment Sampling Range 0-10 cm 421253-320 L70025-3 Sediment Type 23N31. ; 92% Fines 421253-320 L70025-3 Tidal Condition E 421253-320 L70025-3 Total Sulfide Potential low bias: See DAF for details. 421253-320 L70025-4 Ammonia Nitrogen Estimated Value: See DAF for details. 421253-320 L70025-4 Field Personnel HF, BK, CB, SH, JDD 421253-320 L70025-4 Sediment Sampling Range 0-10 cm 421253-320 L70025-4 Sediment Type 23N31. ; 90% Fines 421253-320 L70025-4 Tidal Condition E 421253-320 L70025-4 Total Sulfide Potential low bias: See DAF for details. 421253-320 L70025-5 Ammonia Nitrogen Estimated Value: See DAF for details. 421253-320 L70025-5 Field Personnel HF, BK, CB, SH, JDD 421253-320 L70025-5 Sediment Sampling Range 0-10 cm 421253-320 L70025-5 Sediment Type 23N31. ; 82% Fines 421253-320 L70025-5 Tidal Condition E 421253-320 L70025-5 Total Sulfide Potential low bias: See DAF for details.

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Quality Control Data

King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158029 Total Solids and TVS

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 5/30/2018 8:06 6/6/2018 14:40 6/7/2018 10:59 WG158029‐1,‐2,‐3 L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 5/30/2018 8:06 6/6/2018 14:40 6/11/2018 7:03 WG158029‐1,‐2,‐3 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 5/30/2018 8:46 6/6/2018 14:40 6/7/2018 11:00 WG158029‐1,‐2,‐3 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 5/30/2018 8:46 6/6/2018 14:40 6/11/2018 7:04 WG158029‐1,‐2,‐3 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 5/30/2018 9:16 6/6/2018 14:40 6/7/2018 10:58 WG158029‐1,‐2,‐3 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 5/30/2018 9:16 6/6/2018 14:40 6/11/2018 7:04 WG158029‐1,‐2,‐3 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 5/30/2018 9:42 6/6/2018 14:40 6/7/2018 11:00 WG158029‐1,‐2,‐3 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 5/30/2018 9:42 6/6/2018 14:40 6/11/2018 7:06 WG158029‐1,‐2,‐3 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 5/30/2018 10:17 6/6/2018 14:40 6/7/2018 11:02 WG158029‐1,‐2,‐3 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 5/30/2018 10:17 6/6/2018 14:40 6/11/2018 7:01 WG158029‐1,‐2,‐3 L70174‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOTS SALTWTRSED 5/31/2018 9:28 6/6/2018 14:40 6/7/2018 11:02 WG158029‐1,‐2,‐3 L70174‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTVS SALTWTRSED 5/31/2018 9:28 6/6/2018 14:40 6/11/2018 7:07 WG158029‐1,‐2,‐3 WG158029‐1 MB CVTOTS OTHR SOLID 6/6/2018 14:40 6/7/2018 10:59 WG158029‐1,‐2,‐3 MB1 6/6/18 WG158029‐1 MB CVTVS OTHR SOLID 6/6/2018 14:40 6/11/2018 7:01 WG158029‐1,‐2,‐3 MB1 6/6/18 WG158029‐2 LD CVTOTS SALTWTRSED 6/6/2018 14:40 6/7/2018 11:01 WG158029‐1,‐2,‐3 L70174‐1 WG158029‐2 LD CVTVS SALTWTRSED 6/6/2018 14:40 6/11/2018 7:03 WG158029‐1,‐2,‐3 L70174‐1 WG158029‐3 LT CVTOTS SALTWTRSED 6/6/2018 14:40 6/7/2018 10:59 WG158029‐1,‐2,‐3 WG158029‐2 L70174‐1 WG158029‐3 LT CVTVS SALTWTRSED 6/6/2018 14:40 6/11/2018 7:02 WG158029‐1,‐2,‐3 WG158029‐2 L70174‐1

Page 1 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158222 TOC‐QL

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 5/30/2018 8:06 6/6/2018 15:10 6/14/2018 9:59 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 5/30/2018 8:46 6/6/2018 15:10 6/14/2018 11:52 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 5/30/2018 9:16 6/6/2018 15:10 6/14/2018 12:40 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 5/30/2018 9:42 6/6/2018 15:10 6/14/2018 13:05 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 5/30/2018 10:17 6/6/2018 15:10 6/14/2018 13:29 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70174‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOC‐QL SALTWTRSED 5/31/2018 9:28 6/6/2018 15:10 6/14/2018 13:53 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG158222‐1 MB CVTOC‐QL OTHR SOLID 6/6/2018 15:10 6/14/2018 8:22 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 MB1180606 WG158222‐2 QLCK CVTOC‐QL OTHR SOLID 6/6/2018 15:10 6/14/2018 8:46 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 LEVEL1 WG158222‐3 SB CVTOC‐QL OTHR SOLID 6/6/2018 15:10 6/14/2018 9:11 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG158222‐1 WG158222‐4 LCS CVTOC‐QL OTHR SOLID 6/14/2018 9:35 6/14/2018 9:35 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 LEVEL1 WG158222‐5 LD CVTOC‐QL SALTWTRSED 6/6/2018 15:10 6/14/2018 10:31 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐1 WG158222‐6 LT CVTOC‐QL SALTWTRSED 6/6/2018 15:10 6/14/2018 11:04 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG158222‐5 L70025‐1 WG158222‐7 MS CVTOC‐QL SALTWTRSED 6/6/2018 15:10 6/14/2018 11:28 WG158222‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐1

Page 2 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158247 Total Sulfide

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 5/30/2018 8:06 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 5/30/2018 8:46 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 5/30/2018 9:16 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 5/30/2018 9:42 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 5/30/2018 10:17 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 L70174‐1 421253‐320 South Plant Subtidal NPDES Sediments CVTOTSULFIDE‐QL SALTWTRSED 5/31/2018 9:28 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 WG158247‐1 MB CVTOTSULFIDE‐QL OTHR SOLID 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 MB1 180604 WG158247‐2 SB CVTOTSULFIDE‐QL OTHR SOLID 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 WG158247‐1 WG158247‐3 LD CVTOTSULFIDE‐QL SALTWTRSED 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 L70025‐2 WG158247‐4 LT CVTOTSULFIDE‐QL SALTWTRSED 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 WG158247‐3 L70025‐2 WG158247‐5 MS CVTOTSULFIDE‐QL SALTWTRSED 6/4/2018 9:50 6/4/2018 13:45 WG158247‐2,‐3,‐4,‐5,‐1 L70025‐2

Page 3 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158362 PSD

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 5/30/2018 8:06 6/22/2018 15:30 6/25/2018 9:00 WG158362‐1,‐2 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 5/30/2018 8:46 6/22/2018 15:30 6/25/2018 9:00 WG158362‐1,‐2 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 5/30/2018 9:16 6/22/2018 15:30 6/25/2018 9:00 WG158362‐1,‐2 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 5/30/2018 9:42 6/22/2018 15:30 6/25/2018 9:00 WG158362‐1,‐2 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 5/30/2018 10:17 6/22/2018 15:30 6/25/2018 9:00 WG158362‐1,‐2 L70174‐1 421253‐320 South Plant Subtidal NPDES Sediments CVPSD SALTWTRSED 5/31/2018 9:28 6/22/2018 15:30 6/25/2018 9:00 WG158362‐1,‐2 WG158362‐1 LD CVPSD SALTWTRSED 6/22/2018 15:30 6/25/2018 9:00 WG158362‐1,‐2 L70025‐5 WG158362‐2 LT CVPSD SALTWTRSED 6/22/2018 15:30 6/25/2018 9:00 WG158362‐1,‐2 WG158362‐1 L70025‐5

Page 4 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158652 Ammonia‐Nitrogen (NH3‐KCl)

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 5/30/2018 8:06 6/5/2018 12:00 6/14/2018 9:35 WG158652‐1,‐2,‐3,‐4,‐5,‐6 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 5/30/2018 8:46 6/5/2018 12:00 6/14/2018 9:59 WG158652‐1,‐2,‐3,‐4,‐5,‐6 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 5/30/2018 9:16 6/5/2018 12:00 6/14/2018 10:02 WG158652‐1,‐2,‐3,‐4,‐5,‐6 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 5/30/2018 9:42 6/5/2018 12:00 6/14/2018 10:05 WG158652‐1,‐2,‐3,‐4,‐5,‐6 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 5/30/2018 10:17 6/5/2018 12:00 6/14/2018 10:07 WG158652‐1,‐2,‐3,‐4,‐5,‐6 L70174‐1 421253‐320 South Plant Subtidal NPDES Sediments CVNH3‐KCL SALTWTRSED 5/31/2018 9:28 6/5/2018 12:00 6/14/2018 10:10 WG158652‐1,‐2,‐3,‐4,‐5,‐6 WG158652‐1 MB CVNH3‐KCL OTHR SOLID 6/5/2018 12:00 6/14/2018 9:25 WG158652‐1,‐2,‐3,‐4,‐5,‐6 MB1 6/5/18 12:00 WG158652‐2 SB CVNH3‐KCL OTHR SOLID 6/5/2018 12:00 6/14/2018 9:27 WG158652‐1,‐2,‐3,‐4,‐5,‐6 WG158652‐1 WG158652‐3 LCS CVNH3‐KCL OTHR SOLID 6/5/2018 12:00 6/14/2018 9:30 WG158652‐1,‐2,‐3,‐4,‐5,‐6 LEVEL1 WG158652‐4 LD CVNH3‐KCL OTHR SOLID 6/5/2018 12:00 6/14/2018 9:38 WG158652‐1,‐2,‐3,‐4,‐5,‐6 L70025‐1 WG158652‐5 LT CVNH3‐KCL SALTWTRSED 6/5/2018 12:00 6/14/2018 9:41 WG158652‐1,‐2,‐3,‐4,‐5,‐6 WG158652‐4 L70025‐1 WG158652‐6 MS CVNH3‐KCL SALTWTRSED 6/5/2018 12:00 6/14/2018 9:43 WG158652‐1,‐2,‐3,‐4,‐5,‐6 L70025‐1

Page 5 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158100 Total Mercury by CVAA

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 5/30/2018 8:06 6/8/2018 12:30 6/11/2018 13:21 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 5/30/2018 8:46 6/8/2018 12:30 6/11/2018 13:23 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 5/30/2018 9:16 6/8/2018 12:30 6/11/2018 13:25 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 5/30/2018 9:42 6/8/2018 12:30 6/11/2018 13:27 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments MTHG‐MIDS‐QL SALTWTRSED 5/30/2018 10:17 6/8/2018 12:30 6/11/2018 13:29 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 WG158100‐1 MB MTHG‐MIDS‐QL SOLIDBLANK 6/8/2018 12:30 6/11/2018 13:17 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8MB WG158100‐2 SB MTHG‐MIDS‐QL SOLIDBLANK 6/8/2018 12:30 6/11/2018 13:19 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 WG158100‐1 HG‐SMID WG158100‐3 MS MTHG‐MIDS‐QL SALTWTRSED 6/8/2018 12:30 6/11/2018 13:32 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐5 HG‐SMID WG158100‐4 MSD MTHG‐MIDS‐QL SALTWTRSED 6/8/2018 12:30 6/11/2018 13:34 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 WG158100‐3 L70025‐5 HG‐SMID‐MSD WG158100‐5 SRM MTHG‐MIDS‐QL SALTWTRSED 6/8/2018 12:30 6/11/2018 13:40 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 PACS3 WG158100‐6 SRMD MTHG‐MIDS‐QL SALTWTRSED 6/8/2018 12:30 6/11/2018 13:42 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 WG158100‐5 PACS3 WG158100‐7 QLCK MTHG‐MIDS‐QL SOLIDBLANK 6/8/2018 12:30 6/11/2018 13:45 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 MEDIUM WG158100‐8 QLCK MTHG‐MIDS‐QL SOLIDBLANK 6/8/2018 12:30 6/11/2018 13:47 WG158100‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 MEDIUM

Page 6 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158388 Total Metals by ICP

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L69853‐1 421253‐310 West Point Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 4/25/2018 7:52 6/25/2018 9:00 6/27/2018 9:20 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L69853‐2 421253‐310 West Point Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 4/25/2018 8:39 6/25/2018 9:00 6/27/2018 9:31 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L69853‐3 421253‐310 West Point Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 4/25/2018 9:19 6/25/2018 9:00 6/27/2018 9:08 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L69853‐4 421253‐310 West Point Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 4/25/2018 11:29 6/25/2018 9:00 6/27/2018 9:35 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 5/30/2018 8:06 6/25/2018 9:00 6/27/2018 9:38 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 5/30/2018 8:46 6/25/2018 9:00 6/27/2018 9:42 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 5/30/2018 9:16 6/25/2018 9:00 6/27/2018 9:46 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 5/30/2018 9:42 6/25/2018 9:00 6/27/2018 9:50 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments MTICP‐SED‐QL SALTWTRSED 5/30/2018 10:17 6/25/2018 9:00 6/27/2018 9:53 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 WG158388‐1 SB MTICP‐SED‐QL SOLIDBLANK 6/25/2018 9:00 6/27/2018 8:50 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 WG158388‐2 ICPMARINE WG158388‐2 MB MTICP‐SED‐QL SOLIDBLANK 6/25/2018 9:00 6/27/2018 8:54 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 METHOD BLANK WG158388‐3 LD MTICP‐SED‐QL SALTWTRSED 6/25/2018 9:00 6/27/2018 9:12 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L69853‐3 RPD‐SOL WG158388‐4 MS MTICP‐SED‐QL SALTWTRSED 6/25/2018 9:00 6/27/2018 9:16 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 L69853‐3 ICPMARINE WG158388‐5 LCS MTICP‐SED‐QL SOIL 6/25/2018 9:00 6/27/2018 8:58 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 ERASOIL WG158388‐6 LCSD MTICP‐SED‐QL SOIL 6/25/2018 9:00 6/27/2018 9:01 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 WG158388‐5 ERASOIL WG158388‐7 SRM MTICP‐SED‐QL SALTWTRSED 6/25/2018 9:00 6/27/2018 9:05 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 PACS3 WG158388‐8 QLCK MTICP‐SED‐QL SOLIDBLANK 6/25/2018 9:00 6/27/2018 8:47 WG158388‐1,‐2,‐3,‐4,‐5,‐6,‐7,‐8 HIGH

Page 7 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158323 BNA

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 8:06 6/21/2018 17:00 7/11/2018 13:42 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 8:46 6/21/2018 17:00 7/11/2018 14:18 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 9:16 6/21/2018 17:00 7/11/2018 14:54 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 9:42 6/21/2018 17:00 7/11/2018 15:30 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 10:17 6/21/2018 17:00 7/11/2018 16:07 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG158323‐1 MB ORBNASMS‐NPDESOTHR SOLID 6/21/2018 17:00 7/11/2018 9:26 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 MB180621 WG158323‐2 SB ORBNASMS‐NPDESOTHR SOLID 6/21/2018 17:00 7/11/2018 10:05 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG158323‐1 WG158323‐3 MS ORBNASMS‐NPDESSALTWTRSED 6/21/2018 17:00 7/11/2018 10:41 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐1 WG158323‐4 MSD ORBNASMS‐NPDESSALTWTRSED 6/21/2018 17:00 7/11/2018 11:17 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG158323‐3 L70025‐1 WG158323‐5 SRM ORBNASMS‐NPDESSALTWTRSED 6/21/2018 17:00 7/11/2018 11:53 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG158323‐6 SRMD ORBNASMS‐NPDESSALTWTRSED 6/21/2018 17:00 7/11/2018 12:29 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 WG158323‐5 WG158323‐7 LD ORBNASMS‐NPDESSALTWTRSED 6/21/2018 17:00 7/11/2018 13:06 WG158323‐1,‐2,‐3,‐4,‐5,‐6,‐7 L70025‐2

Page 8 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158325 PCB

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 5/30/2018 8:06 6/21/2018 17:00 6/26/2018 10:40 WG158325‐1,‐2,‐3,‐4,‐5 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 5/30/2018 8:46 6/21/2018 17:00 6/26/2018 10:58 WG158325‐1,‐2,‐3,‐4,‐5 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 5/30/2018 9:16 6/21/2018 17:00 6/26/2018 11:16 WG158325‐1,‐2,‐3,‐4,‐5 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 5/30/2018 9:42 6/21/2018 17:00 6/26/2018 11:34 WG158325‐1,‐2,‐3,‐4,‐5 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments ORPCB‐QL SALTWTRSED 5/30/2018 10:17 6/21/2018 17:00 6/26/2018 11:52 WG158325‐1,‐2,‐3,‐4,‐5 WG158325‐1 MB ORPCB‐QL OTHR SOLID 6/21/2018 17:00 6/26/2018 9:09 WG158325‐1,‐2,‐3,‐4,‐5 MB180621 WG158325‐2 SB ORPCB‐QL OTHR SOLID 6/21/2018 17:00 6/26/2018 9:27 WG158325‐1,‐2,‐3,‐4,‐5 WG158325‐1 WG158325‐3 MS ORPCB‐QL SALTWTRSED 6/21/2018 17:00 6/26/2018 9:45 WG158325‐1,‐2,‐3,‐4,‐5 L70025‐3 WG158325‐4 MSD ORPCB‐QL SALTWTRSED 6/21/2018 17:00 6/26/2018 10:03 WG158325‐1,‐2,‐3,‐4,‐5 WG158325‐3 L70025‐3 WG158325‐5 LD ORPCB‐QL SALTWTRSED 6/21/2018 17:00 6/26/2018 10:22 WG158325‐1,‐2,‐3,‐4,‐5 L70025‐5

Page 9 of 10 King County Environmental Laboratory Batch Report South Plant NPDES Sediment Resampling 30MAY2018

WG158607 BNA‐SIM

Sample Project Project Description List Type Matrix Collect Date Prep Date Anal Date QC Association Comments L70025‐1 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 8:06 6/21/2018 0:00 7/9/2018 13:22 WG158607‐1,‐2,‐3,‐4,‐7 L70025‐2 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 8:46 6/21/2018 0:00 7/9/2018 13:51 WG158607‐1,‐2,‐3,‐4,‐7 L70025‐3 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 9:16 6/21/2018 0:00 7/9/2018 14:21 WG158607‐1,‐2,‐3,‐4,‐7 L70025‐4 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 9:42 6/21/2018 0:00 7/9/2018 14:51 WG158607‐1,‐2,‐3,‐4,‐7 L70025‐5 421253‐320 South Plant Subtidal NPDES Sediments ORBNASMS‐NPDESSALTWTRSED 5/30/2018 10:17 6/21/2018 0:00 7/9/2018 15:21 WG158607‐1,‐2,‐3,‐4,‐7 WG158607‐1 MB ORBNASMS‐NPDESOTHR SOLID 6/21/2018 0:00 7/9/2018 9:53 WG158607‐1,‐2,‐3,‐4,‐7 MB180621 WG158607‐2 SB ORBNASMS‐NPDESOTHR SOLID 6/21/2018 0:00 7/9/2018 10:23 WG158607‐1,‐2,‐3,‐4,‐7 WG158607‐1 WG158607‐3 MS ORBNASMS‐NPDESOTHR SOLID 6/21/2018 0:00 7/9/2018 10:53 WG158607‐1,‐2,‐3,‐4,‐7 L70025‐1 WG158607‐4 MSD ORBNASMS‐NPDESOTHR SOLID 6/21/2018 0:00 7/9/2018 11:22 WG158607‐1,‐2,‐3,‐4,‐7 WG158607‐3 L70025‐1 WG158607‐7 LD ORBNASMS‐NPDESOTHR SOLID 6/21/2018 0:00 7/9/2018 12:52 WG158607‐1,‐2,‐3,‐4,‐7 L70025‐2

Page 10 of 10 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158029 Total Solids and TVS

MB:WG158029‐1 Matrix: OTHR SOLID Listtype:CVTOTS Method:SM2540‐G Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Solids 0.005 0.01 %

MB:WG158029‐1 Matrix: OTHR SOLID Listtype:CVTVS Method:EPA 160.4 Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Volatile Solids 0.005 0.01 %

LT:WG158029‐3 LD:WG158029‐2 L70174‐1 Matrix: SALTWTRSED Listtype:CVTOTS Method:SM2540‐G Project:421253‐320 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Total Solids 0.005 0.01 % 51.5 51.5 51.6 0 0‐‐20

LT:WG158029‐3 LD:WG158029‐2 L70174‐1 Matrix: SALTWTRSED Listtype:CVTVS Method:EPA 160.4 Project:421253‐320 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Total Volatile Solids 0.005 0.01 % 2.26 2.29 2.28 1 0‐‐20

Page 1 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158222 TOC‐QL

MB:WG158222‐1 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Organic Carbon 247 494 mg/Kg

SB:WG158222‐3 MB:WG158222‐1 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Total Organic Carbon 247 494 mg/Kg

LCS:WG158222‐4 Matrix: OTHR SOLID Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project: Pkey:STD (Lab Control Sample) Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit Total Organic Carbon 4770 4770 mg/Kg 33510 33600 100 80‐‐120

LT:WG158222‐6 LD:WG158222‐5 L70025‐1 Matrix: SALTWTRSED Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project:421253‐320 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Total Organic Carbon 1210 1210 mg/Kg 6000 5990 5980 0 0‐‐20

MS:WG158222‐7 L70025‐1 Matrix: SALTWTRSED Listtype:CVTOC‐QL Method:SW846 9060 PSEP96 Project:421253‐320 Pkey:SED (Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit Total Organic Carbon 1200 1200 mg/Kg 6000 11383.3626 15800 86 75‐‐125

Page 2 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158247 Total Sulfide

MB:WG158247‐1 Matrix: OTHR SOLID Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Total Sulfide 0.25 0.499 mg/Kg

SB:WG158247‐2 MB:WG158247‐1 Matrix: OTHR SOLID Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Total Sulfide 0.25 0.499 mg/Kg

LT:WG158247‐4 LD:WG158247‐3 L70025‐2 Matrix: SALTWTRSED Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project:421253‐320 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Total Sulfide 4.92 4.92 mg/Kg 88 91.2 81.4 6 0‐‐20

MS:WG158247‐5 L70025‐2 Matrix: SALTWTRSED Listtype:CVTOTSULFIDE‐QL Method:EPA 9030B/SM4500‐S2‐D Project:421253‐320 Pkey:SED (Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit Total Sulfide 4.96 4.96 mg/Kg 88 33.30678 83.5 ‐14 * 65‐‐135

Page 3 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158362 PSD

LT:WG158362‐2 LD:WG158362‐1 L70025‐5 Matrix: SALTWTRSED Listtype:CVPSD Method:ASTM D422 Project:421253‐320 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Gravel 0.4 4 % 0.5 0.6 0.7 0‐‐20 Sand 0.4 4 % 2.2 2.4 2.6 0‐‐20 Silt 2 4 % 59.4 59.3 59.6 0 0‐‐20 Clay 2 4 % 35.6 35.6 33.7 3 0‐‐20

Page 4 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158652 Ammonia‐Nitrogen (NH3‐KCl)

MB:WG158652‐1 Matrix: OTHR SOLID Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Ammonia Nitrogen 0.02 0.1 mg/Kg

SB:WG158652‐2 MB:WG158652‐1 Matrix: OTHR SOLID Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Ammonia Nitrogen 0.02 0.1 mg/Kg

LCS:WG158652‐3 Matrix: OTHR SOLID Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project: Pkey:STD (Lab Control Sample) Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit Ammonia Nitrogen 0.02 0.1 mg/Kg 0.5 0.385 77 * 80‐‐120

LT:WG158652‐5 LD:WG158652‐4 L70025‐1 Matrix: SALTWTRSED Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project:421253‐320 Pkey:SED (Lab Triplicate, Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value LT Value RSD Qual Lab Limit Ammonia Nitrogen 0.02 0.0984 mg/Kg 1.71 1.76 1.79 2 0‐‐20

MS:WG158652‐6 L70025‐1 Matrix: SALTWTRSED Listtype:CVNH3‐KCL Method:KEROUEL & AMINOT 1997 KCL Project:421253‐320 Pkey:SED (Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit Ammonia Nitrogen 0.02 0.102 mg/Kg 1.71 0.391 2.23 134 * 75‐‐125

Page 5 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158100 Total Mercury by CVAA

MB:WG158100‐1 Matrix: SOLIDBLANK Listtype:MTHG‐MIDS‐QL Method:SW846 7471B Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Mercury, Total, CVAA 0.00238 0.00476 mg/Kg

SB:WG158100‐2 MB:WG158100‐1 Matrix: SOLIDBLANK Listtype:MTHG‐MIDS‐QL Method:SW846 7471B Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Mercury, Total, CVAA 0.00238 0.00476 mg/Kg

MSD:WG158100‐4 MS:WG158100‐3 L70025‐5 Matrix: SALTWTRSED Listtype:MTHG‐MIDS‐QL Method:SW846 7471B Project:421253‐320 Pkey:SED (Matrix Spike Duplicate, Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit True Value MSD Value % Rec. Qual RPD Qual Lab Limit Mercury, Total, CVAA 0.00501 0.00501 mg/Kg 0.0387 0.1 0.137 99 75‐‐125 0.101 0.138 98 0 0‐‐20

SRMD:WG158100‐6 SRM:WG158100‐5 Matrix: SALTWTRSED Listtype:MTHG‐MIDS‐QL Method:SW846 7471B Project: Pkey:SED (Std Reference Material Duplicate, Std Reference Material) Lab Parameter MDL RDL Units True Value SRM Value % Rec. Qual Lab Limit True Value SRMD Value % Rec. Qual RPD Qual Limit Mercury, Total, CVAA 0.0515 0.0515 mg/Kg 2.98 2.87 96 80‐‐120 2.98 2.83 95 2 0‐‐20

Page 6 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158388 Total Metals by ICP

SB:WG158388‐1 MB:WG158388‐2 Matrix: SOLIDBLANK Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Silver, Total, ICP 0.238 0.476 mg/Kg

Page 7 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

MB:WG158388‐2 Matrix: SOLIDBLANK Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Silver, Total, ICP 0.238 0.476 mg/Kg

LD:WG158388‐3 L69853‐3 Matrix: SALTWTRSED Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project:421253‐310 Pkey:SED (Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value RPD Qual Lab Limit Silver, Total, ICP 0.511 0.511 mg/Kg

Page 8 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

MS:WG158388‐4 L69853‐3 Matrix: SALTWTRSED Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project:421253‐310 Pkey:SED (Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit Silver, Total, ICP 0.511 0.511 mg/Kg

LCSD:WG158388‐6 LCS:WG158388‐5 Matrix: SOIL Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project: Pkey:STD (Lab Control Sample Duplicate, Lab Control Sample) Lab Parameter MDL RDL Units True Value LCS Value % Rec. Qual Lab Limit True Value LCSD Value % Rec. Qual RPD Qual Limit Silver, Total, ICP 1.99 1.99 mg/Kg 31.3 28.3 90 75‐‐125 31.3 28.7 92 2 0‐‐20 Arsenic, Total, ICP 9.96 9.96 mg/Kg 145 146 101 79‐‐122 145 144 100 1 0‐‐20 Cadmium, Total, ICP 0.996 0.996 mg/Kg 87.6 86.3 98 80‐‐120 87.6 91.1 104 5 0‐‐20 Chromium, Total, ICP 0.996 0.996 mg/Kg 143 128 90 79‐‐120 143 135 94 5 0‐‐20 Copper, Total, ICP 1.99 1.99 mg/Kg 173 167 97 80‐‐120 173 176 102 5 0‐‐20 Lead, Total, ICP 9.96 9.96 mg/Kg 146 134 92 80‐‐120 146 137 94 2 0‐‐20 Zinc, Total, ICP 0.996 0.996 mg/Kg 194 191 99 80‐‐120 194 195 100 2 0‐‐20

SRM:WG158388‐7 Matrix: SALTWTRSED Listtype:MTICP‐SED‐QL Method:SW846 3050B*SW846 6010D Project: Pkey:SED (Std Reference Material) Parameter MDL RDL Units True Value SRM Value % Rec. Qual Lab Limit Arsenic, Total, ICP 9.92 9.92 mg/Kg 30.3 26.3 87 80‐‐120 Cadmium, Total, ICP 0.992 0.992 mg/Kg 2.23 2.55 114 80‐‐120 Chromium, Total, ICP 0.992 0.992 mg/Kg 90.6 45.2 50 * 80‐‐120 Copper, Total, ICP 1.98 1.98 mg/Kg 326 310 95 80‐‐120 Lead, Total, ICP 9.92 9.92 mg/Kg 188 160 85 80‐‐120 Zinc, Total, ICP 0.992 0.992 mg/Kg 376 356 95 80‐‐120

Page 9 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158323 BNA

MB:WG158323‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Phenol 17 33.3 ug/Kg

Page 10 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

SB:WG158323‐2 MB:WG158323‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Phenol 17 33.3 ug/Kg

Page 11 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

MSD:WG158323‐4 MS:WG158323‐3 L70025‐1 Matrix: SALTWTRSED Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project:421253‐320 Pkey:SED (Matrix Spike Duplicate, Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit True Value MSD Value % Rec. Qual RPD Qual Lab Limit Phenol 17 33.3 ug/Kg

Page 12 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

SRMD:WG158323‐6 SRM:WG158323‐5 Matrix: SALTWTRSED Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project: Pkey:SED (Std Reference Material Duplicate, Std Reference Material) Lab Parameter MDL RDL Units True Value SRM Value % Rec. Qual Lab Limit True Value SRMD Value % Rec. Qual RPD Qual Limit Phenanthrene 170 333 ug/Kg 5200 3400 65 48‐‐112 5200 3260 63 4 0‐‐35 Fluoranthene 170 333 ug/Kg 8800 6500 74 42‐‐127 8800 6430 73 1 0‐‐35 Pyrene 170 333 ug/Kg 9570 5900 62 39‐‐119 9570 5690 59 3 0‐‐35 Benzo(a)anthracene 170 333 ug/Kg 4660 2940 63 41‐‐122 4660 2770 59 6 0‐‐35 Chrysene 170 333 ug/Kg 4800 4280 89 50‐‐144 4800 3760 78 13 0‐‐35 Benzo(b,j,k)fluoranthene 250 500 ug/Kg 8150 6550 80 40‐‐122 8150 6410 79 2 0‐‐35 Benzo(a)pyrene 170 333 ug/Kg 4240 2230 53 31‐‐117 4240 2090 49 7 0‐‐35 Indeno(1,2,3‐Cd)Pyrene 170 333 ug/Kg 2740 1720 63 36‐‐127 2740 1550 56 11 0‐‐35 Dibenzo(a,h)anthracene 170 333 ug/Kg 419 477 114 41‐‐200 419 412 98 14 0‐‐35 Benzo(g,h,i)perylene 170 333 ug/Kg 2800 1330 48 25‐‐133 2800 1030 37 25 0‐‐35

LD:WG158323‐7 L70025‐2 Matrix: SALTWTRSED Listtype:ORBNASMS‐NPDES‐QL Method:SW846 3550B*SW846 8270D Project:421253‐320 Pkey:SED (Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value RPD Qual Lab Limit Phenol 17 33.3 ug/Kg

Page 13 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

2,4,6‐ Tribromo 2‐Fluoro d5‐Nitro Surrogate: phenol phenol benzene d5‐Phenol (Lab Limits) 20‐‐150 20‐‐136 22‐‐126 20‐‐142 L70025‐1 89484945 L70025‐2 139 48 53 47 L70025‐3 131 43 49 44 L70025‐4 168 *627435 L70025‐5 106 45 49 46 WG158323‐1 74606360 WG158323‐2 97626763 WG158323‐3 94576158 WG158323‐4 93566157 WG158323‐5 89717674 WG158323‐6 87627064 WG158323‐7 92434540

Page 14 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158325 PCBs

MB:WG158325‐1 Matrix: OTHR SOLID Listtype:ORPCB‐QL Method:SW846 3550B*SW846 8082A Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Aroclor 1016 0.417 0.833 ug/Kg

SB:WG158325‐2 MB:WG158325‐1 Matrix: OTHR SOLID Listtype:ORPCB‐QL Method:SW846 3550B*SW846 8082A Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Aroclor 1242 0.417 0.833 ug/Kg

MSD:WG158325‐4 MS:WG158325‐3 L70025‐3 Matrix: SALTWTRSED Listtype:ORPCB‐QL Method:SW846 3550B*SW846 8082A Project:421253‐320 Pkey:SED (Matrix Spike Duplicate, Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit True Value MSD Value % Rec. Qual RPD Qual Lab Limit Aroclor 1242 0.833 0.833 ug/Kg

LD:WG158325‐5 L70025‐5 Matrix: SALTWTRSED Listtype:ORPCB‐QL Method:SW846 3550B*SW846 8082A Project:421253‐320 Pkey:SED (Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value RPD Qual Lab Limit Aroclor 1016 0.833 0.833 ug/Kg

Page 15 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

2,4,5,6‐ Tetra chloro m‐ Decachloro Surrogate: xylene biphenyl (Lab Limits) 22‐‐113 51‐‐115 L70025‐17287 L70025‐28192 L70025‐38296 L70025‐48496 L70025‐57794 WG158325‐15399 WG158325‐27598 WG158325‐37786 WG158325‐47796 WG158325‐57492

Page 16 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

Workgroup: WG158607 BNA‐SIM

MB:WG158607‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐SIM‐QL Method:8270D‐SIM Project: Pkey:STD (Method Blank) Parameter MDL RDL Units MB Value Qual Benzyl Alcohol 6.7 16.7 ug/Kg

SB:WG158607‐2 MB:WG158607‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐SIM‐QL Method:8270D‐SIM Project: Pkey:STD (Spike Blank, Method Blank) Parameter MDL RDL Units MB Value True Value SB Value % Rec. Qual Lab Limit Benzyl Alcohol 6.7 16.7 ug/Kg

MSD:WG158607‐4 MS:WG158607‐3 L70025‐1 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐SIM‐QL Method:8270D‐SIM Project:421253‐320 Pkey:STD (Matrix Spike Duplicate, Matrix Spike)

Parameter MDL RDL Units SAMP Value True Value MS Value % Rec. Qual Lab Limit True Value MSD Value % Rec. Qual RPD Qual Lab Limit Benzyl Alcohol 6.7 16.7 ug/Kg

Page 17 of 18 King County Environmental Laboratory QC Report South Plant NPDES Sediment Resampling 30MAY2018

LD:WG158607‐7 L70025‐2 Matrix: OTHR SOLID Listtype:ORBNASMS‐NPDES‐SIM‐QL Method:8270D‐SIM Project:421253‐320 Pkey:STD (Lab Duplicate)

Parameter MDL RDL Units SAMP Value LD Value RPD Qual Lab Limit Benzyl Alcohol 6.7 16.7 ug/Kg

2‐Fluoro d14‐Ter d4‐2‐Chloro Surrogate: biphenyl phenyl phenol (Lab Limits) 30‐‐150 30‐‐150 30‐‐150 L70025‐1 558547 L70025‐2 438050 L70025‐3 497840 L70025‐4 368254 L70025‐5 558146 WG158607‐1 61 101 57 WG158607‐2 449260 WG158607‐3 418153 WG158607‐4 438459 WG158607‐7 487841

======If the following parameters are reported, values in the RPD column are actually Absolute Differences: pH, Field Salinity, Field Sample Depth Sample Temperature, Field

Page 18 of 18

Sample Receipt and Chain of Custody Records

2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Appendix D: Complete Bioassay Results

King County Science and Technical Support Section D-1 November 2018 DATA SUMMARY REPORT 10 DAY AMPHIPOD SEDIMENT TOXICITY TEST #8698 Report Date: August 31, 2018 Test date: June 22, 2018

Sediment Information Toxicity testing on marine sediments was conducted in support of NPDES biomonitoring for the South Plant Treatment Plant. Five sediment samples were collected May 30, 2018 and received by KCEL the day of collection. The samples were identified as L70025-1, -2, -3, -4 and -5. The samples were then logged in and held at 4 ± 2C in the dark (zero-headspace or N purged) until test initiation.

The reference sediment was collected by KCEL staff from Carr Inlet, WA, on May 31, 2018. Upon arrival the sediment was logged in as L70174-1 and held at 4 ± 2C in the dark (zero-headspace or N purged) until test initiation.

The negative control sediment was collected at the Ampelisca collection location in San Francisco Bay on June 12, 2018. Negative control sediment was dry sieved and rinsed 3X (24 hour settling) with clean seawater.

Copies of COC forms are provided in Appendix D.

Table 1. Sediment information.

KCEL Collect Holding %Fines % Fines Diff Sample # Locator Date Time (days) (Laser PSD) From Refsed NA CONTROL 6/12/18 10 Fine-grain - L70174-1 REFSED 5/31/18 22 81.5 - L70025-1 STP820NE 5/30/18 23 96.9 15.4 L70025-2 STP610MN 5/30/18 23 93.9 12.4 L70025-3 STP570MS 5/30/18 23 95.9 14.4 L70025-4 STP460S 5/30/18 23 98.6 17.1 L70025-5 STP770SE 5/30/18 23 95 13.5

The % fines for all test sediments were within 20% (absolute) of the reference sediment percent fines.

Testing was initiated June 22, 2018 and the sediment holding time was 23 days, holding time for control sediment was 10 days and reference sediment was 22 days. Testing was completed within the 56-day holding time outlined in the project SAP.

Dilution Water Information Natural sea water (SW) used for conducting the toxicity tests was obtained from the NMFS/NOAA laboratory in Mukilteo, WA on June 19, 2018. The water was filtered through a 0.45 m Gelman filter, salinity adjusted to 28 ppt with aerated laboratory-grade DI water, aerated before use and stored at < 20C until use.

Test Methods The reference procedures for development of this SOP are the ASTM (1993) “Standard guide for conducting 10-day static sediment toxicity tests with marine and estuarine amphipods” (ASTM E-1367-62) and The Puget Sound Water Quality Authority (1995) “Recommended guidelines for conducting laboratory bioassays on Puget Sound sediments." Statistical analysis and interpretive criteria are derived from Washington State Department of Ecology Sediment Cleanup User’s Manual (SCUM II) (WDOE. 2017). Mortality is the primary endpoint recorded in this test. A daily emergence endpoint is also reported. There is no reburial endpoint for Ampelisca (PSWQA, 1995).

Test Conditions Test conditions for the toxicity tests with Ampelisca abdita are summarized in Table 2.

1

Table 2 Summary of test conditions using Ampelisca abdita.

Organism: Ampelisca abdita Size: 3-5 mm Loading Rate: 20 organisms per test chamber Test Chamber: 1 liter beaker with watch glass covers # of Replicate Chambers: 5 replicate test chambers and 1 water quality chamber per sediment Volume of Sediment: 175 mL of sediment per test chamber Volume of Seawater: 775 mL per test chamber Water Quality Chamber: 775 mL seawater and 175 mL sediment Overlying/Dilution Water: Sea water filtered to 0.45 m, salinity adjusted to 28 ppt w/ aerated de-ionized water; aerated before use; stored at < 20C Negative Control: Sediment from organism collection location (dry-sieved and sea water-rinsed) Positive Control: Cadmium in sea water only (no sediment) # of Replicate Positive Control 2 replicate test chambers for each concentration, 1 water quality Chambers: chamber for control (0 mg/L) and highest concentration Reference Sediment: Carr Inlet, WA sediment Test Duration: 10 days (sediment test) and 4 days (positive control) Test Temperature: 20 ± 1C Test Illumination: Continuous light for sediment test. Positive control dark. Aeration: Gently, maximum 100 bubbles per minute for the test. Positive control no aeration. pH: 7 to 9 Salinity: 28 ± 1 ppt Dissolved Oxygen: 5 to 10 mg/L Food: None

Test Organism The amphipods, Ampelisca abdita, were collected by Brezina and Associates from San Francisco Bay, CA, on June 19, 2018. The organisms were shipped overnight in plastic bags with a mat of sediment tubes, filled with seawater and sealed. Upon arrival at the laboratory on June 21, 2018 organisms were placed into a 20oC environmental chamber under continuous light and aeration until used for testing. The amphipods were not fed during the holding period.

Amphipod Sediment Toxicity Test The amphipods were exposed to the test sediments, negative control and reference sediment for 10 days. The day before test initiation, each test sediment was thoroughly mixed and any large stones, organic material or live animals removed. A volume of 175 mL of test sediment was placed in 1-L beakers and covered with 775 mL of filtered seawater (28 ± 1 ppt). The beakers were covered with watch glasses, placed in an Environmental Chamber 8556, fitted with aeration lines and left to equilibrate overnight. Five replicates plus a sixth beaker for water quality measurements were prepared for the test sediments, negative control and reference sediment. The following day (Day 0) each beaker was seeded with 20 amphipods. The amphipods were sieved from their holding containers using a 1-mm sieve and randomly distributed to plastic weigh boats containing < 20C, 28 ppt seawater. Each weigh boat contained ten amphipods. The health and counts were confirmed, after which the amphipods were randomly distributed among the beakers by adding the contents of two weigh boats to each beaker.

Samples for ammonia and sulfide were taken from water quality beakers prior to loading the amphipods and from the test beakers at test termination. Measurements of temperature, salinity, dissolved oxygen and pH were taken from water quality beakers prior to loading the amphipods, daily and at test termination. Temperature was measured daily in six beaker positions (4 corner + 2 center) as well as at 15-minute intervals using an Onset TIDBIT recorder (Onset Computer Corp., 2006). Salinity was adjusted as needed by adding approximately 15 mL de-ionized water to obtain a 1 ppt decrease. The beakers were checked daily for mortality and emergence of amphipods. Any

2 amphipods that had become trapped by surface tension at the air/water interface were gently re-submerged using a glass pipette.

The test was terminated after 10 days when the sediments were sieved through a 0.5-mm screen, and live and dead amphipods were counted and removed. Missing amphipods were assumed to have died and decomposed prior to termination of the test. The amphipod sediment toxicity test (KCEL test #8698) was started at 1100h on June 22, 2018 and terminated at 0700-0915h on July 2, 2018.

Positive Control Two positive control (reference toxicant) tests were conducted concurrently with the sediment test using cadmium chloride (CdCl2) and ammonium chloride (NH4Cl) as the reference toxicants. Two replicates of each of the five concentrations (0.175, 0.35, 0.7, 1.4 and 2.8 mg Cd/L or 31.25, 62.5, 125, 250 and 500 mg NH4-N/L) and a seawater-only control (0 mg/L) were prepared as a dilution series. The tests were performed in 400-mL beakers each containing 250 mL of test solution and 20 amphipods. Testing was conducted over 96 hours with water quality measurements recorded daily. The 96-h LC50 value (expressed as mg/L Cd or NH4 as N) was calculated by CETIS v. 1.8.1.2 (Tidepool Scientific 2011). The tests were used to assess the relative health and sensitivity of the amphipods by comparing the results to the acceptability range of current laboratory control limits. The positive control tests (KCEL test #8706 and 8707) were started at 1100h on June 22, 2018 and terminated at 1030 on June 26, 2018.

Test Acceptability Test acceptance criteria along with results of sediment and positive control (reference toxicant) tests with Ampelisca abdita are listed in Table 3.

Table 3 Ampelisca abdita test acceptability criteria with reference toxicant test results.

Sediment Test KCEL #8698 Reference Toxicant Tests Parameter Control Reference Endpoint: Sediment Sediment 96-Hour LC50 % Survival % Survival Acceptance ≥ 90% ≥ 75% Within current lab limits Criteria: (mean ± 2SD) Results: 95 % 86 % Cd, mg/L LC50 = 0.41 Control Limits: 0.12 – 1.11 (updated 7/18/18) Total Ammonia, mg/L LC50 = 64 Control Limits: In development

This test meets all test acceptance criteria.

Sediment Toxicity Test Results Results of the amphipod toxicity test (KCEL test #8698) are summarized in Attachment 1. Complete results including raw data and statistical printouts are provided in Appendix A.

For test #8698, mean survival in the negative control sediment was 95%, which was greater than the acceptance criterion of 90%. Mean survival in the reference sediment was 86%, meeting the acceptance criterion of ≥ 75%. Test sediment response ranged from 80 to 86 % survival. Mean avoidance (emergence) in the test ranged from 0.6 to 1.6 amphipods/beaker/day.

Using BioStat Bioassay Data Analysis Application, no station demonstrated mortality greater than 25% on an absolute basis or statistical effect compared to the SMS Marine SQS Standard. Comparison to the SMS Interpretive Criteria is summarized in Table 4.

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Table 4: SMS Marine Biological Criteria (SQS/SCO & CSL and performance standards)

Performance Standards Interpretive Criteria Endpoint Control Reference SQS/SCO CSL MT > 25% MT – MR > 30% Absolute and LIMS 10-Day % and MT vs. MR Locator MC < 10% MR < 25% MT vs. MR Number mortality Stat Sig (p = Stat Significant 0.05) (p = 0.05) NA CONTROL 5 PASS L70174-1 REFSED 14 PASS L70025-1 STP820NE 15 PASS NA L70025-2 STP610MN 14 PASS NA L70025-3 STP570MS 16 PASS NA L70025-4 STP460S 17 PASS NA L70025-5 STP770SE 20 PASS NA C = Control; R = Reference; T = Test; F = Final; M = Mortality; SD = Significantly Different. For the Amphipod test, a statistical significance at p = 0.05 equals an exceedance of the criteria. SQS – Sediment Quality Standard SCO – Sediment Cleanup Objective CSL – Cleanup Screening Level

Water Quality Data The water quality measurements taken during the test are summarized in Attachment 2. Sulfides, ammonia and un- ionized ammonia calculations are provided in Attachment 3.

Data Flags None

Protocol Deviations Minor salinity deviations greater than 28 ± 1 ppt were adjusted as needed by adding approximately 15 mL de- ionized water to obtain a 1 ppt decrease.

Minor temperature deviations of 18.8 C and 18.9 C occurred on Day 2 in the green (REFSED) and white (STP460S) lab codes.

References

ASTM. 1993. Standard guide for conducting 10-day static sediment toxicity tests with marine and estuarine amphipods. ASTM E-1367-62. American Society for Testing and Materials, Philadelphia, PA.

ACOE. 2006. BioStat 2.0. U.S. Army Corps of Engineers, Seattle District. Puget Sound Water Quality Authority. 1995. Recommended guidelines for conducting laboratory bioassays on Puget Sound sediments. Prepared for U.S. EPA, Region 10, Office of Puget Sound, Seattle, WA.

USEPA, 1994. Methods for assessing the toxicity of sediment-associated contaminates with estuarine and marine amphipods. EPA 600/R-94/025.

WDOE. 2017. Sediment Cleanup User’s Manual (SCUM II). Washington Department of Ecology, Olympia, WA. Revised December 2017. https://fortress.wa.gov/ecy/publications/1209057.html

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Attachment 1: Endpoint Summary

Attachment 2: Water Quality Summary

Attachment 3: Ammonia and Sulfide Data

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Appendix E: Summary of Chemistry Results Compared to Marine Sediment Criteria

King County Science and Technical Support Section E-1 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

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King County Science and Technical Support Section E-2 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Table E-1. 2017 and 2018 South Plant outfall sediment chemistry results compared to appropriate SMS criteria. Results in red text were detected above the CSL. SMS 2017 2018 Parameter SQS CSL STP820NE STP460N STP625NP STP610MN STP570MS STP625SP STP460S STP770SE STP820NE STP610MN STP570MS STP460S STP770SE Conventionals % % Total Solids -- -- 28.9 30.3 31.2 31.2 31.3 32.6 30.8 32.8 30.5 31.7 31.1 32.0 31.4 % Total Volatile Solids -- -- 2.78 2.86 2.92 2.91 2.95 2.88 2.97 2.92 3.02 2.86 2.84 2.83 3.06 % Clay -- -- 43.5 44.4 44.6 42.7 46.1 42.0 52.8 42.9 36.4 35.2 36.0 33.5 35.6 % Silt -- -- 58.7 58.5 56.8 56.3 52.3 60.0 46.7 49.4 60.6 58.7 59.9 65.1 59.4 % Sand -- -- 1.5,

King County Science and Technical Support Section E-3 July 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

SMS 2017 2018 Parameter SQS CSL STP820NE STP460N STP625NP STP610MN STP570MS STP625SP STP460S STP770SE STP820NE STP610MN STP570MS STP460S STP770SE Total HPAHs 960 5300 11 6.7 10 7.1 7.7 6.1 8.7 64 11 10 8.5 9.1 11 Chlorobenzenes mg/Kg OC 1,2-Dichlorobenzene 2.3 2.3

King County Science and Technical Support Section E-4 July 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Appendix F: Complete Benthic Taxonomy Data

King County Science and Technical Support Section F-1 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

Table F-1. Complete benthic taxonomy results by replicate including abundances by lowest taxonomic level. Benthic index calculations are included at the bottom of the table.

STP820NE STP460N STP625NP STP610MN Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Phylum: Annelida Class: Clitellata Oligochaeta Class: Polychaeta Family: Capitellidae Barantolla americana 2 4 Heteromastus filiformis 3 3 Heteromastus filobranchus 3 4 1 Heteromastus sp. Mediomastus sp. Family: Cossuridae Cossura bansei 1 1 1 Family: Maldanidae Maldane glebifex 1 2 Metasychis disparidentatus Praxillella praetermissa Family: Opheliidae Ophelina acuminata 1 1 1 1 5 5 1 4 1 1 Travisia brevis 1 Order: Aciculata Family: Glyceridae Glycera americana 1 Glycera nana 1 1 4 2 1 1 2 1 3 2 2 2 Family: Goniadidae Glycinde armigera 2 1 Glycinde picta 1 Goniada brunnea 1 3 1 1 2 1 1 Goniada maculata 1 1 Family: Hesionidae Podarkeopsis glabrus 1 1 Family: Lumbrineridae Scoletoma luti Scoletoma tetraura Complex 1 Family: Nephtyidae Nephtys ferruginea 2 1 3 3 2 4 1 1 5 4 4 Family: Onuphidae Onuphis iridescens 5 4 5 2 2 5 4 3 4 5 6 Family: Pholoidae Pholoides asperus

King County Science and Technical Support Section F-2 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP820NE STP460N STP625NP STP610MN Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Family: Phyllodocidae Phyllodoce groenlandica 1 1 Family: Polynoidae Gattyana treadwelli 2 1 Halosydna johnsoni 1 1 Hesperonoe complanata 2 1 5 1 3 3 1 3 7 Lepidasthenia longicirrata Lepidonotus squamatus 1 Malmgreniella baschi 1 3 1 Malmgreniella scriptoria Tenonia priops 1 Family: Sphaerodoridae Sphaerodorum pillifera Order: Canalipalpata Family: Ampharetidae Ampharete acutifrons 3 2 3 2 3 Ampharete finmarchica Ampharetinae 1 1 3 1 Family: Cirratulidae Chaetozone columbiana** 1 Cirratulidae 1 Family: Flabelligeridae Brada pilosa 2 3 1 1 1 2 Family: Oweniidae Galathowenia oculata 1 Family: Pectinariidae Pectinaria californiensis 1 1 1 Family: Sabellidae Bispira pacifica Megalomma splendida Family: Spionidae Laonice cirrata 2 3 1 3 6 1 3 2 2 2 Paraprionospio alata 2 1 4 3 2 1 2 2 1 3 2 Prionospio (Minuspio) lighti 1 2 Prionospio sp. 2 Prionospio steenstrupi 1 Family: Sternaspidae Sternaspis fossor 1 1 Family: Terebellidae Neoamphitrite robusta 1 Pista moorei Pista wui 1

King County Science and Technical Support Section F-3 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP820NE STP460N STP625NP STP610MN Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Thelepus setosus Family: Trichobranchidae Terebellides californica 1 Order: Orbiniida Family: Orbiniidae Leitoscoloplos pugettensis 1 2 4 3 1 4 3 2 1 Family: Paraonidae Aricidea (Acmira) lopezi Levinsenia gracilis 2 1 1 1 Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Order: Amphipoda Family: Ampeliscidae Ampelisca careyi 1 1 Ampelisca sp.* 1 1 Ampelisca unsocalae 1 Family: Calliopiidae Calliopius sp. 1 Family: Eusiridae Eusirus columbianus 1 3 1 1 1 Rhachotropis barnardi 2 1 1 1 1 Family: Isaeidae Protomedeia articulata 4 Family: Ischyroceridae Ericthonius rubricornis Family: Lysianassidae Orchomenella decipiens 1 Orchomenella pacificus 1 1 1 Family: Melitidae Desdimelita californica 2 Desdimelita desdichada 1 1 1 1 2 1 2 Family: Oedicerotidae Bathymedon sp. 2 1 1 2 1 1 2 Family: Phoxocephalidae Harpiniopsis sp. 4 3 1 Heterophoxus affinis 4 5 2 6 7 11 5 4 2 1 2 Paraphoxus sp. 5 3 5 1 7 2 1 Family: Podoceridae Dulichia rhabdoplastis 1 Family: Synopiidae Bruzelia tuberculata 1 1 1 3

King County Science and Technical Support Section F-4 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP820NE STP460N STP625NP STP610MN Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Family: Uristidae Anonyx sp. 5 2 1 1 1 Order: Cumacea Family: Diastylidae Diastylis pellucida 2 3 3 1 2 1 1 1 1 2 Leptostylis sp. 1 Family: Leuconidae Eudorella sp. 3 1 2 1 Eudorellopsis integra 2 4 10 1 6 9 2 2 3 4 Leucon sp. 3 3 4 2 1 1 1 Order: Decapoda Family: Hippolytidae Eualus avinus 3 3 1 Eualus butleri 1 Eualus sp.* 1 Spirontocaris holmesi 1 1 1 1 Spirontocaris sica 1 1 1 3 1 Infraorder: Caridea Caridea 1 1 1 1 Family: Pasiphaeidae Pasiphaea pacifica** 1 Infraorder: Brachyura Superfamily: Majoidea Majoidea Superfamily: Cancridae Cancridae 1 Superfamily: Xanthoidea Family: Panopeidae Panopeidae 1 Superfamily: Pinnotheroidea Family: Pinnotheridae Pinnixa sp. 2 5 5 1 1 5 1 2 2 Infraorder: Axiidae Calocarides spinulicauda 1 1 1 1 1 Order: Mysida Family: Mysidae Pseudomma truncatum 1 1 Subphylum: Chelicerata Class: Pycnogonida Order: Pantopoda Family: Phoxichilidiidae Anoplodactylus viridintestinalis

King County Science and Technical Support Section F-5 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP820NE STP460N STP625NP STP610MN Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Phylum: Mollusca Class: Aplacophora Family: Chaetodermatidae Chaetoderma sp. 1 4 2 4 2 1 3 2 3 4 7 Class: Bivalvia Order: Myoida Family: Hiatellidae Hiatella arctica Order: Nuculoida Family: Nuculidae Acila castrensis 1 2 Ennucula tenuis Family: Yoldiidae Megayoldia martyria 1 Megayoldia thraciaeformis 1 Yoldia seminuda 1 Order: Veneroida Family: Cardiidae Cardiidae* Nemocardium centifilosum 1 1 Family: Lucinidae Lucinoma annulatum 1 2 Parvilucina tenuisculpta 10 10 13 4 4 13 14 15 12 7 7 7 Family: Tellinidae Macoma calcarea 40 29 24 27 27 27 35 27 20 27 10 19 Family: Thyasiridae Axinopsida serricata 111 87 83 104 53 112 79 82 86 35 73 46 Family: Veneridae Compsomyax subdiaphana 1 Class: Gastropoda Gastropoda* 1 1 Order: Archaeogastropoda Family: Fissurellidae Cranopsis cucullata Order: Cephalaspidea Family: Aglajidae Melanochlamys diomedea 1 Family: Cylichnidae Cylichna attonsa 1 1 Order: Neotaenioglossa Family: Capulidae Trichotropis cancellata

King County Science and Technical Support Section F-6 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP820NE STP460N STP625NP STP610MN Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Family: Cerithiidae Lirobittium sp. 1 1 Family: Epitoniidae Epitonium sp. 1 Family: Rissoidae Alvania compacta Phylum: Cnidaria Class: Anthozoa Order: Actiniaria Actiniaria 1 Phylum: Echinodermata Class: Asteroidea Asteroidea Class: Echinoidea Order: Spatangoida Family: Schizasteridae Brisaster latifrons 1 1 2 1 4 2 Class: Holothuroidea Order: Dendrochirotida Family: Phyllophoridae Pentamera lissoplaca Order: Molpadiida Family: Molpadiidae Molpadia intermedia 2 7 9 6 5 6 6 4 13 8 10 6 Class: Ophiuroidea Order: Ophiurida Family: Amphiuridae Amphiuridae 1 1 1 1 1 Family: Ophiuridae Ophiura sp. 1 Phylum: Echiura Order: Bonelliida Family: Bonelliidae Nellobia eusoma 2 Order: Echiuroinea Family: Echiuridae Arhynchite pugettensis Phylum: Nemertea Class: Anopla Family: Tubulanidae Tubulanus polymorphus 1 2 1 Order: Heteronemertea

King County Science and Technical Support Section F-7 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP820NE STP460N STP625NP STP610MN Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Family: Lineidae Micrura sp. 1 Class: Enopla Enopla 1 Order: Hoplonemertea Family: Emplectonematidae Paranemertes californica** 1

Benthic Index Calculations Total Abundance 226 174 205 214 134 207 196 192 182 128 157 138 Crustacea 36 15 31 31 26 20 33 28 22 11 14 20 Mollusca 163 130 122 141 87 152 131 127 123 78 95 83 Polychaeta 24 22 40 35 14 28 24 25 22 28 35 28 Misc. 3 7 12 7 7 7 8 12 15 11 13 7 Total Richness 36 25 37 36 30 25 33 35 31 36 33 33 Crustacea 15 6 14 11 13 9 12 14 11 10 10 11 Mollusca 5 4 4 6 5 3 6 4 6 9 5 8 Polychaeta 14 14 15 17 10 11 12 12 12 13 15 12 Misc. 2 1 4 2 2 2 3 5 2 4 3 2 Total Biomass 52.6 143 220 196 132 112 114 60.7 210 236 359 148 Crustacea 0.50 0.06 0.20 0.20 0.40 0.20 0.10 1.30 0.40 0.90 0.20 0.10 Mollusca 0.76 0.75 0.92 0.64 0.81 0.99 5.73 0.76 0.50 21.99 0.51 2.76 Polychaeta 0.92 1.27 1.28 1.20 0.70 1.68 0.55 1.12 0.86 16.46 9.60 4.03 Misc. 50.4 141 218 194 130 109 108 57.5 208 197 349 142 Pielou's Evenness 0.588 0.608 0.698 0.629 0.679 0.579 0.643 0.662 0.641 0.754 0.675 0.759 Shannon-Wiener (loge) 2.09 1.91 2.52 2.24 2.31 1.84 2.23 2.35 2.14 2.68 2.36 2.65 Swartz's Dominance 5 4 10 7 7 4 5 7 6 9 8 10 *Deleted for purposes of richness calculations (included in abundance calculations) **Collapsed to higher level for diversity calculations

STP570MS STP625SP STP460S STP770SE Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Phylum: Annelida Class: Clitellata Oligochaeta 1 1 Class: Polychaeta Family: Capitellidae Barantolla americana 1 4 3 Heteromastus filiformis 2 1 Heteromastus filobranchus Heteromastus sp. 6 Mediomastus sp. 2 1 Family: Cossuridae Cossura bansei 1 1

King County Science and Technical Support Section F-8 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP570MS STP625SP STP460S STP770SE Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Family: Maldanidae Maldane glebifex Metasychis disparidentatus 1 Praxillella praetermissa 1 Family: Opheliidae Ophelina acuminata 2 1 1 2 1 3 1 1 1 Travisia brevis Order: Aciculata Family: Glyceridae Glycera americana Glycera nana 2 2 1 2 1 2 2 1 1 1 3 1 Family: Goniadidae Glycinde armigera 1 1 1 2 1 Glycinde picta Goniada brunnea 1 1 1 2 3 1 1 Goniada maculata 1 Family: Hesionidae Podarkeopsis glabrus 1 Family: Lumbrineridae Scoletoma luti 1 Scoletoma tetraura Complex Family: Nephtyidae Nephtys ferruginea 3 2 1 3 1 3 1 4 1 2 Family: Onuphidae Onuphis iridescens 3 1 4 7 3 6 2 4 8 3 3 1 Family: Pholoidae Pholoides asperus 4 Family: Phyllodocidae Phyllodoce groenlandica 1 Family: Polynoidae Gattyana treadwelli Halosydna johnsoni 3 Hesperonoe complanata 3 6 1 1 3 1 2 2 Lepidasthenia longicirrata 1 1 1 2 1 Lepidonotus squamatus Malmgreniella baschi Malmgreniella scriptoria 1 1 1 2 2 1 Tenonia priops Family: Sphaerodoridae Sphaerodorum pillifera 1 Order: Canalipalpata Family: Ampharetidae

King County Science and Technical Support Section F-9 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP570MS STP625SP STP460S STP770SE Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Ampharete acutifrons 1 3 7 1 2 1 2 5 3 Ampharete finmarchica 2 1 Ampharetinae* Family: Cirratulidae Chaetozone columbiana** Cirratulidae Family: Flabelligeridae Brada pilosa 2 1 2 1 8 2 1 1 1 Family: Oweniidae Galathowenia oculata 1 Family: Pectinariidae Pectinaria californiensis 1 Family: Sabellidae Bispira pacifica 1 Megalomma splendida 10 Family: Spionidae Laonice cirrata 2 1 1 2 4 5 1 2 3 2 2 Paraprionospio alata 1 2 2 2 3 1 1 1 1 3 1 3 Prionospio (Minuspio) lighti Prionospio sp. Prionospio steenstrupi Family: Sternaspidae Sternaspis fossor 1 Family: Terebellidae Neoamphitrite robusta Pista moorei 1 1 Pista wui 1 Thelepus setosus 1 Family: Trichobranchidae Terebellides californica Order: Orbiniida Family: Orbiniidae Leitoscoloplos pugettensis 3 1 2 3 1 3 2 2 3 1 Family: Paraonidae Aricidea (Acmira) lopezi 1 1 1 Levinsenia gracilis 1 1 1 1 1 1 1 Phylum: Arthropoda Subphylum: Crustacea Class: Malacostraca Order: Amphipoda Family: Ampeliscidae Ampelisca careyi 1 1

King County Science and Technical Support Section F-10 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP570MS STP625SP STP460S STP770SE Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Ampelisca sp.* Ampelisca unsocalae Family: Calliopiidae Calliopius sp. 1 Family: Eusiridae Eusirus columbianus 1 1 1 Rhachotropis barnardi 1 1 1 Family: Isaeidae Protomedeia articulata 1 2 Family: Ischyroceridae Ericthonius rubricornis 26 Family: Lysianassidae Orchomenella decipiens Orchomenella pacificus 1 Family: Melitidae Desdimelita californica 1 Desdimelita desdichada 1 2 1 1 1 1 1 1 1 Family: Oedicerotidae Bathymedon sp. 1 1 2 4 2 1 2 Family: Phoxocephalidae Harpiniopsis sp. 2 1 1 1 1 1 1 7 4 Heterophoxus affinis 4 2 1 2 1 3 4 2 4 6 1 Paraphoxus sp. 1 1 2 1 1 Family: Podoceridae Dulichia rhabdoplastis Family: Synopiidae Bruzelia tuberculata 1 1 1 1 Family: Uristidae Anonyx sp. 1 1 1 Order: Cumacea Family: Diastylidae Diastylis pellucida 2 1 2 2 3 1 1 2 5 2 Leptostylis sp. Family: Leuconidae Eudorella sp. 2 1 1 Eudorellopsis integra 5 5 2 2 4 2 2 5 1 5 7 6 Leucon sp. 1 1 2 1 2 1 Order: Decapoda Family: Hippolytidae Eualus avinus 1 1 Eualus butleri Eualus sp.* 1

King County Science and Technical Support Section F-11 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP570MS STP625SP STP460S STP770SE Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Spirontocaris holmesi 1 1 1 1 Spirontocaris sica 1 Infraorder: Caridea Caridea Family: Pasiphaeidae Pasiphaea pacifica** Infraorder: Brachyura Superfamily: Majoidea Majoidea 1 Superfamily: Cancridae Cancridae Superfamily: Xanthoidea Family: Panopeidae Panopeidae Superfamily: Pinnotheroidea Family: Pinnotheridae Pinnixa sp. 3 5 3 2 1 2 5 4 4 Infraorder: Axiidae Calocarides spinulicauda 2 2 1 Order: Mysida Family: Mysidae Pseudomma truncatum 1 1 1 1 Subphylum: Chelicerata Class: Pycnogonida Order: Pantopoda Family: Phoxichilidiidae Anoplodactylus viridintestinalis 1 Phylum: Mollusca Class: Aplacophora Family: Chaetodermatidae Chaetoderma sp. 3 6 2 5 3 4 1 2 5 1 Class: Bivalvia Order: Myoida Family: Hiatellidae Hiatella arctica 1 Order: Nuculoida Family: Nuculidae Acila castrensis 1 2 Ennucula tenuis 1 1 Family: Yoldiidae Megayoldia martyria 1 Megayoldia thraciaeformis

King County Science and Technical Support Section F-12 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP570MS STP625SP STP460S STP770SE Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Yoldia seminuda 1 Order: Veneroida Family: Cardiidae Cardiidae* 1 Nemocardium centifilosum 1 Family: Lucinidae Lucinoma annulatum 2 1 Parvilucina tenuisculpta 7 11 5 8 10 4 9 7 4 3 8 8 Family: Tellinidae Macoma calcarea 18 26 23 20 21 15 22 38 22 35 26 32 Family: Thyasiridae Axinopsida serricata 69 114 83 55 80 76 55 88 98 103 92 110 Family: Veneridae Compsomyax subdiaphana Class: Gastropoda Gastropoda* Order: Archaeogastropoda Family: Fissurellidae Cranopsis cucullata 1 Order: Cephalaspidea Family: Aglajidae Melanochlamys diomedea Family: Cylichnidae Cylichna attonsa 2 Order: Neotaenioglossa Family: Capulidae Trichotropis cancellata 1 Family: Cerithiidae Lirobittium sp. 2 1 1 2 3 1 Family: Epitoniidae Epitonium sp. Family: Rissoidae Alvania compacta 1 1 Phylum: Cnidaria Class: Anthozoa Order: Actiniaria Actiniaria Phylum: Echinodermata Class: Asteroidea Asteroidea 1 Class: Echinoidea Order: Spatangoida

King County Science and Technical Support Section F-13 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP570MS STP625SP STP460S STP770SE Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Family: Schizasteridae Brisaster latifrons 2 2 2 2 2 1 2 3 Class: Holothuroidea Order: Dendrochirotida Family: Phyllophoridae Pentamera lissoplaca 1 Order: Molpadiida Family: Molpadiidae Molpadia intermedia 8 6 6 5 8 5 6 7 5 5 7 4 Class: Ophiuroidea Order: Ophiurida Family: Amphiuridae Amphiuridae 1 Family: Ophiuridae Ophiura sp. Phylum: Echiura Order: Bonelliida Family: Bonelliidae Nellobia eusoma 1 1 2 1 1 1 Order: Echiuroinea Family: Echiuridae Arhynchite pugettensis 1 Phylum: Nemertea Class: Anopla Family: Tubulanidae Tubulanus polymorphus 1 1 1 Order: Heteronemertea Family: Lineidae Micrura sp. Class: Enopla Enopla Order: Hoplonemertea Family: Emplectonematidae Paranemertes californica**

Benthic Index Calculations Total Abundance 164 212 156 128 192 152 129 242 169 201 205 197 Crustacea 23 23 13 12 20 13 14 45 13 22 31 22 Mollusca 99 158 113 85 118 102 90 142 127 145 135 152 Polychaeta 31 21 20 24 43 32 14 43 20 28 32 17 Misc. 11 10 10 7 11 5 11 12 9 6 7 6 Total Richness 38 32 30 28 34 30 28 45 26 33 35 28 Crustacea 12 12 8 9 12 10 7 11 8 10 10 9 Mollusca 6 5 4 4 6 7 4 10 5 6 6 5

King County Science and Technical Support Section F-14 November 2018 2017 South Plant NPDES Outfall Sediment Sampling Event: Final Results

STP570MS STP625SP STP460S STP770SE Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Rep Taxa 1 2 3 1 2 3 1 2 3 1 2 3 Polychaeta 17 11 14 13 13 12 12 19 10 15 18 11 Misc. 3 4 4 2 3 1 5 5 3 2 1 3 Total Biomass 240 350 171 114 84.1 136 240 312 245 138 262 95.9 Crustacea 0.20 0.20 0.20 0.10 0.30 0.10 0.10 0.20 0.30 0.80 0.05 0.20 Mollusca 0.58 0.79 0.46 0.41 0.79 0.60 0.72 1.81 0.83 1.02 0.93 0.75 Polychaeta 1.82 0.92 1.05 2.64 1.65 2.17 0.86 1.40 1.68 1.39 1.76 1.79 Misc. 238 348 169 111 81.3 134 238 309 242 135 259 93.2 Pielou's Evenness 0.698 0.576 0.585 0.677 0.697 0.647 0.667 0.668 0.547 0.581 0.657 0.543 Shannon-Wiener (loge) 2.54 2.00 1.99 2.25 2.44 2.20 2.22 2.54 1.78 2.03 2.34 1.81 Swartz's Dominance 10 5 4 6 8 7 6 8 3 5 8 3 *Deleted for purposes of richness calculations (included in abundance calculations) **Collapsed to higher level for diversity calculations

King County Science and Technical Support Section F-15 November 2018