APPENDIX H Water Quality Regulatory Issues - Total Maximum Daily Loads and Related Strategies

The following are excerpts from Basin Plan Total Maximum Daily Load documents and Phase 1 of the COCIRCWMP. See the References section for links to the complete documents. Also included here are some suggested strategies that may be appropriate to each TMDL.

Sediment TMDL http://www.ocwatersheds.com/watersheds/tmdls_sediment_intro.asp

The U.S. EPA established TMDLs for sediment, nitrogen, and phosphorus for Newport Bay and San Diego Creek, CA on April 13, 1998. EPA subsequently approved slightly revised TMDLs submitted by the State of for sediment, nitrogen, and phosphorus for Newport Bay and San Diego Creek on April 16, 1999. These State-adopted TMDLs supersede the TMDLs previously established by EPA.

Sediment TMDL quantifiable objectives (Resolution No. 98-101 - Attachment Basin Plan Total Maximum Daily Load for Sediment in the Newport Bay/San Diego Creek Watershed)

ƒ “Reduce the annual average sediment load in the watershed from a total of approximately 250,000 tons per year to 125,000 tons per year, thereby reducing the sediment load to Newport Bay to approximately 62,500 tons per year and limiting sediment deposition in the drainages to approximately 62,500 tons per year. Sediment control measures shall be implemented and maintained to result in a 50% reduction in the current load of sediment in the Newport Bay/San Diego Creek Watershed within 10 years.” ƒ Sediment control measures shall be implemented and maintained to comply with the following Load Allocations (implemented as 10-year running annual averages) for discharges of sediment to Newport Bay: 1. No more than 28,000 tons per year of sediment shall be discharged to Newport Bay from open space areas within the watershed, 2. No more than 19,000 tons per year shall be from agricultural land, 3. No more than 13,000 tons per year from construction sites, 4. No more than 2,500 tons per year discharged from urban areas. ƒ “If these acreages are changed by more than 1% as the result of sediment deposition, if the minimum depth (7’) is not maintained, and if the 50% target sediment reduction described below is not achieved, the Regional Board may consider appropriate enforcement action.” ƒ Amend 1% habitat change to a more measurable criterion (11-07 sediment workshop suggestion)

Strategies for sediment reduction

ƒ Foothill and in channel basins – coarse sediment ƒ Revegetation of open space – coarse and fine sediment ƒ Bank stabilization – coarse and fine sediment ƒ In-stream sediment basins ƒ Dredging UNB –fine sediment ƒ Capture and decrease – coarse and fine sediment ƒ NTS – coarse and fine sediment in low flow runoff ƒ Existing construction BMPs – coarse and fines ƒ Slow down flow where feasible with meanders, drop structures, etc.

Conclusions from Sediment TMDL Annual Reports

The following are excerpts from the 2006-2007 Sediment TMDL Annual Report:

The sediment discharges for each of the stations are the lowest recorded since sediment monitoring began at each station, a reflection of the historically low rainfall amount received during the year. (July 1,2006 – June 30,2007)

Channel Erosion Studies Channel erosion studies have been conducted as part of the sediment monitoring program since the mid-1980’s under the auspices of Dr. Stanley W. Trimble from the UCLA Department of Geography. The purpose of these studies is to inspect channel conditions, inventory channel profiles in light of urban development and construction, and as a result, aid in understanding the effect of channel erosion on the sediment load entering Newport Bay. Channel conditions were last studied and mapped by Dr. Trimble in 1997 and 2001. Results from his recent study show that channel erosion in San Diego Creek has been greatly curtailed over the past quarter century and that there has been a dramatic decrease in the length of erosionally unstable channels over the period. As a specific example, channel length described as extremely unstable in this report was 1.8 miles, compared to the 9.3 miles present in 1998.

Dr. Trimble notes Borrego Wash and continue to be partially unstable and that while Borrego continues to erode and furnish significant quantities of sediment downstream, the reach appears to be naturally moving towards an equilibrium, which is reducing channel erosion there. The 2006 Channel Erosion Study can be found in Appendix E (of the 2007-2007 Annual Report).

Open Space Area Sediment Loading Evaluation In May 2007 Fehlman Consulting Services, Inc. began work on a new study designed to look at the contribution of sediment from the open space areas of the watershed. The study will estimate the sediment loading rate that will occur from the different land uses under the full build-out condition of the watershed. The study will also evaluate the feasibility of sediment load management in the open space areas of the watershed. Completion of the study is expected to take place in mid 2008, with results presented in the 2007-08 Annual Report.

Analysis of Sediment Trends

The following are excerpts from the 2005-06 Sediment TMDL Annual Report:

The available data indicates that sediment loads in the San Diego Creek watershed are reduced significantly from rates recorded in the pre-TMDL period.

At the Campus Drive monitoring location on San Diego Creek, sediment discharges measured during the 2004-05 period are lower than had previously been measured for the entire range of measured flow rates. There has been a progressive reduction in sediment discharge versus flow discharge relationship in recent years. The reduction in sediment load has been predominantly associated in a reduction in the load of fine materials.

At the Culver Drive monitoring location on San Diego Creek, the trends are less clear. The sediment discharge versus flow relationship for 2004-05 is lower than the 1997-98 period, but generally higher than measurements from the 2002-03 period. Any general reduction in sediment load since 1997-98 has been associated with decrease in fine sediment load – the coarse sediment load relationship appears to have remained constant.

At the Barranca Parkway monitoring location on , the sediment discharges measured during the 2004-05 period are lower than had previously been measured for the entire range of measured flow rates. There has been a progressive reduction in sediment discharge versus flow discharge relationship in recent years. Both coarse and fine sediment load curves have significantly lowered since the 1997-98 monitoring period.

As the San Diego Creek watershed becomes further developed, less and less watershed supply of sediment is released during storm events. This results in less sediment load entering the channels.

At the Campus Drive and Culver Drive locations, little change has been observed in the amount of coarse sediment load the flow is carrying at a particular flow rate, while at Barranca Parkway, the coarse sediment load has decreased. At both Campus Drive and Culver Drive, the San Diego Creek channel has an abundance of material for transport, and the channel properties are relatively constant – thus the mechanisms controlling bed material (coarse) transport capacity have not changed. At Barranca Parkway, however, the channel shows evidence of incisement and the bed material is coarsening. Thus, the coarse material transport has shown reduction since the bed material size has increased. Over time, as the coarse material load from watershed supply to Peters Canyon continues to decline, the bed material will continue to coarsen. The process will continue until the reach becomes naturally armored, which may occur simultaneously with slope adjustment.

The remaining monitoring gages within the San Diego Creek watershed have record periods that are too short to assess any long-term trends. The loading estimated during the recent major precipitation period (2004/05) can be contrasted with the expected average annual loading computed for the preliminary load allocation and monitoring plan reports to provide more indication of current trends. This comparison indicates that contributions from the urban, construction, and agriculture land use portions of the watershed (predominantly represented by monitoring gages at the Santa Ana-Dehli, Bonita Canyon and Marshburn Channel, respectively) are less than had been estimated in the load allocation and monitoring plan study. These data indicate that open space land use areas are becoming more significant as contributors to the total sediment yield from the watershed.

As development continues in the watershed, the open space portions of the watershed will be increasingly the dominant land use type providing watershed sediment yield to the channel and Bay, particularly the fine sediment fraction of the total load. The non-armored channels will adjust in response to the coarse material supply available from these areas, and the channel beds will coarsen and/or flatten in response to reduced loading, a trend that is now observable in Peters Canyon. The coarser and/or flatter channels will ultimately transport sediment loads at rates in balance with the watershed supply.

Nutrients (Nitrogen and Phosphorus) http://www.ocwatersheds.com/watersheds/tmdls_nutrient_intro.asp

Table 5-9a. Summary of Loading Targets and Compliance Time Schedules. (Attachment to Resolution No. 98-9, as amended by Resolution 98-100) TMDL December 31, 2002 December 31, 2007 December 31, 2012 Newport Bay Watershed 200,097 lbs. 153,861 lbs. TN – Summer Load3 Newport Bay Watershed 144,364 lbs. TN – Winter Load 4 Newport Bay Watershed 86,912 lbs. 62, 080 lbs. TP Annual Load5

San Diego Creek, Reach 2 14 lbs. TN – Daily Load6

Table 5-9b. Seasonal Load Allocations of Total Nitrogen for the Newport Bay Watershed Nutrient TMDL 1990-1997 2002 2002 2007 2007 2012 2012 Loading Allocation Summer Allocation8 Summer Allocation8 Winter Allocation Allocation Allocation (April- (April- (Oct- Sept)8 Sept)8 Mar)7,8,11 Newport Bay lbs/year lbs/day lbs/season lbs/day lbs/season lbs/day Lbs/season Watershed TN2 TN10 TN TN10 TN TN10 TN

Wasteload Allocation Hines Nurseries 96,360 224 40,992 211 38,613 211 14,227 TIN1 Bordiers Nursery 30,660 TIN 71 12,993 67 12,261 67 4,518 El Modeno Gardens 18,250 TIN 43 7,869 40 7,320 40 2,607 Unpermitted nurseries ------3 30 5,490 24 4,392 24 1,618 Nursery subtotal 67,344 62,586

IRWD WWSP 0 62 62 62 4,181 (permanent discharge)9 Silverado Constructors 0 141 25,671 141 25,671 141 9,459 ETC4 Urban runoff 277,1316 20,785 16,628 55,442 Wasteload 113,800 104,885 92,142 Allocation

Load Allocation Agricultural discharges 328,0406 22,963 11,481 38,283 Undefined sources (Open space, atmospheric deposition, rising groundwater, ------3 63,334 37,495 13,939 cleanup/ dewatering, in-bay nitrogen) Load allocation 86,297 48,976 52,222

Total 200,097 153,861 144,364 1,087,0005 5 year 10 year 15 year target target target 1 TIN = (NO3 + NH3). 2 TN = (TIN + Organic N). 3 Unknown 4 Wasteload allocation of a 50% reduction in nitrogen concentration upon commencement of discharge. 5 1990-1997 annual average (summer loading and winter loading). 6 Estimated annual average (summer and winter loading). 7 Total nitrogen winter loading limit applies between October 1 and March 31 when mean daily flow rate at San Diego Creek and Campus Drive is below 50 cubic feet per second (cfs), and when the mean daily flow rate at San Diego Creek and Campus Drive is above 50 cubic feet per second (cfs), but not as the result of precipitation. 8 Compliance to be achieved no later than this date. The Regional Board may require earlier Compliance with these targets when it is feasible and reasonable. 9 Daily load limit applies upon commencement of discharge. 10 Lbs/day TN (monthly average). 11 Assumes 67 non-storm days.

Table 5-9e. Schedule of Actions to Achieve Water Quality Objectives from Nutrient TMDL

Program Actions 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Review and revision of water quality objectives X New nursery permits X Revise existing permits X Nurseries X NPDES permit X Groundwater X cleanup/dewatering Agricultural nutrient management plans X Urban runoff BMP plan X Sediment TMDL implementation X Monitoring X Newport Bay Watershed total nitrogen -summer TMDL targets X X Newport Bay Watershed total nitrogen - winter TMDL targets X Newport Bay Watershed total phosphorus – annual TMDL X X targets San Diego Creek, Reach 2 total nitrogen-daily target X Evaluation of TMDL X X X X X X

Strategies for nutrients (nitrogen and phosphorus)

• Desalter groundwater project – existing • Nitrogen & Selenium Management Program - County • Existing nursery nutrient management plans • Existing agricultural nutrient management plans • Urban runoff BMPs as part of existing Drainage Area Management Plan • Street sweeping (leaves) & no parking signs on sweeping days • Drought tolerant landscape design- voluntary by public education and by landscape ordinance per existing state laws and/or city ordinances. • Rebates for replacing lawns – lower fertilizer use and irrigation runoff. • Golf course, playing field and park turf BMPs • Improve recycled water processing to lower nutrient content

Other Salts No existing TMDL exists but a high salts content is a problem in the aquifer. Strategies to address this could include:

• Existing Groundwater Replenishment System (OCWD/OCSD) – increase output in future • Decrease salts content of recycled water – IRWD & e.g. wetland at top of Great Park Canyon • Desalter groundwater projects

Toxics & Heavy Metals http://www.ocwatersheds.com/watersheds/tmdls_toxics_intro.asp

Introduction (Source: COCIRCWMP, Phase 1, p. 2-51)

The Santa Ana Regional Water Quality Control Board is in the process of reviewing the EPA promulgated Toxics TMDL and has decided to break it down into five separate constituent and geographically specific TMDLs. The five resulting TMDLs include:

1. Organophosphate Pesticides (diazinon and chlorpyrifos) 2. Selenium 3. Organochlorinated Compounds (chlordane, dieldrin, DDT, PCBs, toxaphene) 4. Metals (cadmium, copper, lead, zinc) 5. Rhine Channel (copper, lead, selenium, zinc chromium, mercury)”

(From Organochlorine TMDL document) Organophosphate (OP) Pesticides—diazinon and chlorpyrifos are two organophosphatepesticides with similar sources and impairment primarily limited to San Diego Creek.

Selenium—is a toxic bioaccumulative metal, with significant groundwater sources

Organochlorinated compounds—PCBs, DDT, chlordane, dieldrin and toxaphene have similar fate (bioaccumulation) and transport mechanisms (primarily from watershed soils to freshwater and saltwater sediments) for all waterbodies.

Metals—cadmium, copper, lead and zinc have similar aqueous behavior and affect nearly all water bodies

Each of these individual TMDLs must proceed through the full State approval process before they are officially adopted. Currently, the only TMDL to begin the State approval process is the organophosphate pesticide (diazinon and chlorpyrifos) TMDL.

When the Regional Board considers adoption of TMDLs for toxic pollutants along with associated implementation plans, the State may adopt the TMDLs identified in this decision or further assess these pollutants and adopt different TMDLs if warranted. EPA’s TMDLs do not contain compliance timeframes or interim implementation targets because these elements are addressed by the State in the implementation planning process.

Table 1-1. Toxic Pollutants per Waterbody Requiring TMDL Development Waterbody (Type) Element/ Metal Organic Compound San Diego Creek Cd, Cu, Pb, Se, Zn Chlorpyrifos, Diazinon, (freshwater) Chlordane, Dieldrin, DDT, PCBs, Toxaphene Cd, Cu, Pb, Se, Zn Chlorpyrifos, Chlordane, DDT, (saltwater) PCBs Lower Newport Bay Cu, Pb, Se, Zn Chlordane, Dieldrin, DDT, PCBs (saltwater) Rhine Channel within Lower Cu, Pb, Se, Zn, Cr, Chlordane, Dieldrin, DDT, PCBs Newport Bay (saltwater) Hg Newport Bay Toxic Pollutant TMDLs, 2002

Toxics TMDL Measurements

TMDLs (and thus, load allocations and wasteload allocations) can be expressed as “mass per time, toxicity, or other appropriate measure”, depending on the type of waterbody and the sources that contribute to impairment. The TMDLs for all pollutants except diazinon and chlorpyrifos are expressed in terms of mass loads per time, and the TMDLs for the pesticides diazinon and chlorpyrifos are expressed in terms of water column concentrations. It is appropriate to express these pesticide TMDLs in terms of water column concentrations because these pollutants cause adverse effects on aquatic life through relatively short term exposures. These pollutants are relatively short-lived in the environment before they break down into less toxic forms, and they do not bioaccumulate through the food chain in the same way several of the other pollutants addressed in these TMDLs do. Therefore, the water column concentrations of these pesticides are of greatest concern in preventing adverse ecosystem effects.

Toxic Pollutant TMDLs and Newport Bay/San Diego Creek Concentrations (Table 2.11), (From COCIRCWMP, Phase 1, Regional Description) presents the TMDLs and the concentrations of pesticides and metals contained in samples collected from San Diego Creek, Upper and Lower Newport Bay, and the Rhine Channel.

Table 2.11 Toxic Pollutant TMDLs and Newport Bay/San Diego Creek Concentrations

Criteria 2002 Concentrations San Upper Lower Rhine Diego New- New- Chan- Fresh- Creek port port nel Pollutant Type of Location Criterion water Saltwater (ug/l) Bay Bay (ug/l) Compound (ug/l) (ug/l) (ug/l) (ug/l) Diazinon Organo- San Diego Chronic 0.05 0.2 0.202 phosphate Creek Pesticide Acute 0.08 Chlor- Organo- San Diego Chronic 0.014 0.009 0.111 0.0433 pyrifos phosphate Creek Pesticide Acute 0.02 0.02

Selenium Metal San Diego Chronic 5 22.1 Creek Acute 20 71 (dissolved ) Cadmium Metal San Diego Acute 8.9 to 19.1 42 0.13- 0.095- - - Creek for large 0.27 0.22 flows to baseflows Chronic 4.2 to 6.2 9.3 for Table 2.11 Toxic Pollutant TMDLs and Newport Bay/San Diego Creek Concentrations

Criteria 2002 Concentrations San Upper Lower Rhine Diego New- New- Chan- Fresh- Creek port port nel Pollutant Type of Location Criterion water Saltwater (ug/l) Bay Bay (ug/l) Compound (ug/l) (ug/l) (ug/l) (ug/l) medium flows to baseflows Copper Metal San Diego Acute 25.5 to 50 4.8 2.4-5.5 3.4-29.0 8.2- - Creek for large 26.3 flows to baseflows Chronic 18.7 to 3.1 29.3 for medium flows to baseflows Lead Metal San Diego Acute 134 to 281 210 0.05- 0.023- 0.03- - Creek for large 0.35 0.96 0.89 flows to baseflows Chronic 6.3 to 10.9 8.1 for medium flows to baseflows Zinc Metal San Diego Acute 208 to 379 90 2.6- 10-100 2.5- - Creek for large 23.1 11.5 flows to baseflows Chronic 244 to 382 81 for medium flows to baseflows PCBs Organo- San Diego Chronic 0.014 ND ND chlorine Creek Pesticides DDT Organo- San Diego Acute 1.1 ND ND chlorine Creek Pesticides Chronic 0.001

Chlordane Organo- San Diego Acute 2.4 ND ND chlorine Creek Pesticides Chronic 0.0043

Dieldrin Organo- San Diego Acute 0.24 ND ND chlorine Creek Pesticides Chronic 0.056

Toxaphene Organo- San Diego Acute 0.73 ND ND chlorine Creek Pesticides Chronic 0.0002 Source: EPA 2002; metal data from Newport Bay Toxics TMDL Part E. NA – not analyzed ND – not detected DNQ – detected but not quantified Chronic means 4 consecutive day average

Organophosphate pesticides – diazinon and chlorpyrifos

Chlorpyrifos – In June 2000, the EPA published its revised risk assessment and agreement with registrants for chlorpyrifos (USEPA 2000b). The agreement imposes new restrictions on chlorpyrifos use in agriculture, cancels or phases out nearly all indoor and outdoor residential uses, and also cancels non-residential uses where children may be exposed. Application rates for non-residential areas where children will not be exposed will be reduced, and public health use for fire ant eradication and mosquito control will be restricted to professionals. In Orange County, residential use likely accounts for over 90% of total chlorpyrifos use. Thus, it appears that over 90% of the current chlorpyrifos use in the Newport Bay watershed will be eliminated by the EPA agreement. Retail sales are scheduled to stop by December 31, 2001, and structural uses will be phased out by December 31, 2005. We are concerned by potential conflicts between programs to reduce use of these pesticides and mandates to use these pesticides for fire ant control. EPA urges that Regional Board to work with the State Water Resources Control Board, California Department of Pesticide Regulation, California Department of Food and Agriculture, and EPA’s pesticide program to assess and, if necessary, reconcile these potentially conflicting mandates concerning OP pesticide use.

If monitoring demonstrates that the urban use phase-outs are inadequate to implement the TMDLs, it may be necessary in the future to implement additional controls on agricultural uses of these pesticides in coordination with the California Department of Pesticide Regulation

Chlorpyrifos was detected less frequently (in 45% of samples) than diazinon. This is due in part, to the lower solubility of chlorpyrifos, and its greater affinity for sediment. The lower mobility of chlorpyrifos results in lower concentrations in the drainage channels. The only residential site with relatively high chlorpyrifos concentrations was Westcliff Park (stormflow), but the baseflow concentrations were relatively low.

Diazinon – In January 2001, USEPA released a revised risk assessment and an agreement with registrants to phase out most diazinon uses (USEPA 2001b). Under the agreement, all indoor uses will be terminated, and all outdoor non-agricultural uses will be phased out over the next few years. In addition, on a national basis, about one-third of the agricultural crop uses will be removed. Within the Newport Bay watershed, non-agricultural and non-nursery uses account for over 90% of the diazinon use in Orange County. It is thus likely that the EPA agreement will result in the cessation of most diazinon use in the Newport Bay watershed soon after the outdoor non-agricultural use registration expires on December 31, 2004.

At virtually all the locations, the median stormflow concentration is significantly higher than the median baseflow concentration. Since stormwater runoff constitutes about 80% of the volume of water discharged to Newport Bay on an annual basis, this would indicate that the overwhelming majority of the pesticide load would derive from stormflow rather than baseflow.

Available data and studies indicate that in normal use, OP pesticides break down quickly and therefore only a small percentage of the total amount applied is available to runoff to waterbodies. However, even small amounts of these pesticides are enough to cause acute and chronic toxicity in receiving water bodies. In addition, land use analyses indicate that commercial nurseries and residential areas are associated with high pesticide application rates, and much higher detection in water during wet weather. Similar studies reported in literature of pesticide use and water monitoring results have indicated that residential hotspots (individual homes) can account for most of the diazinon runoff from a neighborhood (Scanlin and Feng 1997; Cooper 1996).

Table 3-2. Diazinon and Chlorpyrifos Allocations for San Diego Creek (Fresh Water) Category Diazinon (ng/L) Chlorpyrifos (ng/L) Acute Chronic Acute Chronic Wasteload Allocation 72 45 18 12.6 Load Allocation 72 45 18 12.6 MOS 8 5 2 1.4 TMDL 80 50 20 14 Chronic means 4-consecutive day average

Table 3-3. Chlorpyrifos Allocations for Upper Newport Bay (Salt Water) Category Acute Chronic (ng/L) (ng/L) Wasteload Allocation 18 8.1 Load Allocation 18 8.1 MOS 2.0 0.9 TMDL 20 9 Chronic means 4-consecutive day average

Selenium – TMDLs in development

TMDLs are required for selenium (Se) for San Diego Creek, Upper Bay, Lower Bay, and Rhine Channel.

Selenium is a naturally occurring element that persists in soils and aquatic sediments and readily bioaccumulates through the food chain at levels that can cause adverse effects on higher level aquatic life and wildlife including fish and birds that prey on fish and invertebrates. Selenium can become mobilized and concentrated by weathering and evaporation in the process of soil formation and alluvial fan deposition in arid and semiarid climates (Presser, 1994). Moreover, selenium may be leached from sediments as a result of irrigation practices, elevation of the groundwater table, or other modifications in the natural hydrologic regime.

The TMDL analysis found that the most significant sources of Se loading appear to be associated with groundwater entering surface waters (sometimes directly and sometimes through discharge from dewatering operations). Control of these sources will be difficult. However, EPA recommends that the State begin working with permitted dischargers to assess options for reducing Se discharges through discharge management practices and/or treatment technologies.

Dissolved selenium concentrations in San Diego Creek at Campus, and in tributaries to San Diego Creek, consistently exceed the chronic (4-day average) CTR criterion for freshwaters (5 ⎧g/L). This has been observed in numerous studies, which also cite occasional exceedances of the acute (1 hour max.) criterion (Hibbs and Lee 1999, IRWD 1999, Lee and Taylor 2001a). Dissolved selenium concentrations in Newport Bay do not exceed the CTR saltwater criterion (71 ⎧g/L); nonetheless, fish tissue data indicate that selenium loadings may be causing toxicity or contributing to conditions threatening wildlife in Upper and Lower Bay (see next paragraph). Freshwater and saltwater toxicity tests (designed for metals and trace elements such as selenium) are currently in progress (SCCWRP 2001a, b).

Table 4-1. Numeric Targets for Selenium in San Diego Creek and Newport Bay (µ/L) Waterbody type Total Se * Dissolved Se# Acute Chronic San Diego Creek / freshwater 20 5 N/A Newport Bay & Rhine Channel / saltwater N/A N/A 71 *Total recoverable = unfiltered sample # Dissolved + <0.45 µm filter

Figure 4-1 summarizes the sources of selenium in the watershed. The significance of these sources varies both on discharge location and season of the year. Nursery runoff shows moderate concentrations (~10 ⎧g/L) in dry weather and are potential sources during storms (Lee and Taylor 2001a). There is some evidence that runoff from open space, hillsides, and agricultural lands are significant sources during rain events although this evidence is inconclusive. Groundwater seepage/infiltration, treated groundwater discharges, and groundwater dewatering discharges represent significant and constant sources.

An investigation of selenium sources shows that shallow groundwater is a significant and constant source of selenium to surface waters in the San Diego Creek watershed (Hibbs and Lee 2000). Groundwater may seep into surface waters via natural processes or it may be pumped as part of groundwater cleanup or dewatering operations which discharge into surface waters. Thus selenium contributions to the watershed include both non-point sources (seepage) and point sources (cleanup and dewatering).

Of the load from San Diego Creek, , which conveys selenium from selenium-laden shallow groundwater, represents the major source in dry weather. These sources may include runoff from hillsides, open spaces, agricultural lands, and commercial nursery sites. High concentrations were found in nursery channels during rain events, although it remains unclear if the selenium sources are from the commercial nurseries or from sources existing upstream of the nurseries. During rain events, the selenium load from the upper reach of San Diego Creek was comparable to that from Peters Canyon Wash, suggesting runoff from open space is a significant source during rain events. Low concentrations were found in nursery channels during baseflow conditions.

EPA adopted the selenium allocation scheme developed by Regional Board staff for their draft selenium TMDL.

Table 4-5 shows the wasteload and load allocations for San Diego Creek. The estimated current annual load is considered as the current load of selenium at Campus Drive based on IRWD monitoring data (4/98- 3/99). The selenium TMDLs and allocations are expressed in mass-based annual loads. Daily loads could be calculated by dividing the annual TMDLs and allocations by 365. However, annual loading-based TMDLs and allocations are more appropriate because prospective adverse effects associated with selenium are associated more with long term mass loadings and bioaccumulation effects than with short term or acute effects. An explicit margin of safety (MOS) of 10% was included to account for uncertainty in the analysis and ensure compliance with water quality objectives.

Discharges from groundwater cleanup and groundwater dewatering are significant sources and loading from those operations depends on their location. However, the quantification of loading from individual discharges is not feasible at this time due to lack of selenium data in effluent from those operations. In this TMDL, allocations are assigned as group allocations groundwater cleanup discharges and groundwater dewatering discharges. In addition, a separate wasteload allocation is provided to account for future new groundwater dewatering discharges.

Table 4-5. Selenium Allocations for San Diego Creek Watershed Source Loading Capacity Current Estimated (lbs/yr) Load ¥ reductions Tier 1 Tier 2 Tier 3 Tier 4 Annual Total* WLA MCAS Tustin 1.6 2.0 1.8 7.9 13.2 GW clean up 6.2 7.8 7.5 36.9 58.4 Silverado GW 3.1 3.9 4.0 21.1 32.1 GW dewatering 3.9 4.9 4.5 21.1 34.3 Future GW 0.4 0.5 0.5 2.6 4.0 Facilities § Stormwater 0.4 1.0 1.0 5.3 7.6 Permit WLA Subtotal 15.5 20.0 19.3 94.8 149.7

LA All nurseries 3.1 3.9 4.0 21.1 32.1 Ag runoff 5.4 7.3 8.0 44.8 65.6 Undefined 53.4 66.4 69.1 366.2 555.0 Sources # LA Subtotal 61.9 77.6 81.1 432.0 652.6

Total allocations 77.4 97.6 100.5 526.8 802.3 2443 67%

MOS 89.1

Total TMDL 891.4 * Sum of loading capacity for San Diego Creek only (based on 5 µ/L applied to all flow tiers) # Undefined sources includes: open space and hillside runoff, shallow GW and saltwater Se ¥ Current load based on IRWD Se data (1998-99) and corresponding ODPFRD flow records § Other GW facilities refers to future permits

Selenium Concentrations in Groundwater Sources, 1999-2005 Range of Selenium Sub-watershed Concentrations (µg/L) Concentration Limits (µg/l) San Diego Creek, Reach 1 3.15-187 2-5 San Diego Creek, Reach 2 1.87-12.8 2-5 Peters Canyon Wash 2.6-270 2-5 Santa Ana-Delhi Channel 7.69-106 2-5 Sources: COCIRCWMP, Phase 1, & Sources and Loads and Identification of Data Gaps for Selenium – Nitrogen and Selenium Management Program.

Current strategy for selenium management

ƒ Cienega pilot project for groundwater cleanup ƒ Nitrogen & Selenium Management Program ƒ Ongoing studies, Dr. Barry Hibbs

Organochlorine TMDLs

The term “organochlorine compounds” includes all of these pollutants and the phrase “organochlorine (OC) pesticides” refers to DDT, chlordane, dieldrin and toxaphene. Use of these pollutants has been banned because of potential harm to human health and/or wildlife. However, many of the environmental concerns associated with their use and ultimate transport to the environment are directly related to their ability to persist in water, soil, and biological tissue for long periods of time after their introduction to the environment. (From www.ocwatersheds.com)

Table F-2. Sediment Targets Used in the TMDL Analyses PCBs DDT Chlordane Dieldrin Toxaphene Waterbody (pg/kg)* (pg/kg)* (pg/kg)* (pg/kg)* (pg/kg)* San Diego Creek 34.1 6.98 4.5 2.85 0.1 Upper Newport Bay 21.5 3.89 2.26 NR NR Lower Newport Bay 21.5 3.89 2.26 0.71 NR Rhine Channel 21.5 3.89 2.26 0.71 NR NR: TMDL not required for these pollutant-waterbody combinations *Dry Weight Organochlorine Compounds TMDL Update Wanda Marquis-Smith, Senior Environmental Scientist, Santa Ana RWQCB, 7/30/03

Table 6-1a. Numeric Targets for Organochlorine Compounds for all Waterbodies Sediment target ° (µg/dry kg or Fish tissue target # Waterbody Pollutant ppm) (µg/kg wet or ppb) San Diego Creek and tributaries Chlordane 4.5 30 Dieldrin 2.85 2.0 Total DDT 6.98 100 Total PCBs 34.1 20 Toxaphene 0.1* 30

Chlordane 2.26 30 Upper and Lower Newport Bay and Dieldrin 0.72 2.0 Rhine Channel Total DDT 3.89 100 Total PCBs 21.5 30

* this value assumes 1% total organic carbon in sediment sample

° sediment targets equivalent to threshold effect levels (TEL) from Buchman 1999, except toxaphene from NY Dpt. Environmental Conservation

# All tissue targets from OEHHA

Organochlorine Compounds TMDL Update Wanda Marquis-Smith, Senior Environmental Scientist, Santa Ana RWQCB, 7/30/03

Table 6-1a By selecting sediment targets, EPA will address protection of benthic organisms as well as bioaccumulation of these organochlorine compounds into tissues of higher organisms such as fish, wildlife predators and humans. Sediment targets are used for TMDL development except where sediment data were not available; e.g., toxaphene in San Diego Creek. The alternate targets – fish tissue screening values from OEHHA and water column objectives from the CTR– are included in this TMDL report as means of gauging improvement in the water quality and progress towards achievement of the TMDL, and to assist in assessing the accuracy of the analysis supporting the TMDLs

Table 6-9. Allocations for San Diego Creek Watershed DDT Chlordane Dieldrin Category Type (including PCBs Toxaphene (pg/kg)* (pg/kg)* Dicofol) Urban Runoff 302.8 220.3 183.4 177.7 6.2 Caltrans 8.7 6.3 5.2 42.3 0.2 Other NPDES WLA 34.6 25.2 21.0 5.6 0.7 Permittees 209.6 225.6 Sub-total 346.1 g/yr 251.8 g/yr 7.1 g/yr g/yr g/yr

Ag Runoff 8.6 6.2 5.2 5.6 0.2 LA Undefined * 34.6 25.2 21.0 22.6 0.7 Sub-total 43.2 g/yr 31.4 g/yr 26.2 g/yr 28.2 g/yr 0.9 g/yr

MOS 43.3 g/yr 31.5 g/yr 26.2 g/yr 28.2 g/yr 0.9 g/yr

Total 262.0 282.0 432.6 g/yr 314.7 g/yr 8.9 g/yr TMDL g/yr g/yr

* Undefined = existing sediments + air deposition Total TMDL = WLA + LA + MOS (Margin of Safety) Organochlorine Compounds TMDL Update Wanda Marquis-Smith, Senior Environmental Scientist, Santa Ana RWQCB, 7/30/03

Two potential routes of environmental exposure of these compounds are of greatest potential concern— ongoing loadings from the watershed of historically deposited pollutants and exposures to organochlorine compounds already present in aquatic sediments (principally in Newport Bay). There is substantial evidence indicating that levels of these compounds in Bay sediments and aquatic organisms has declined over the past 20 years or more. On the other hand, resuspension of sediments to which organochlorine pollutants have adhered is likely to be a more important “loading” source. (The U.S. Army Corps of Engineers will be) removing sediment from containment basins in Upper Newport Bay. We recommend that the State work with the project sponsors to ensure that potential disturbance of sediments containing the pollutants addressed in this TMDL report is considered in the design process and minimized during project implementation. One of the major routes for the OC compounds to enter Newport Bay and its tributaries is believed to be runoff and erosion processes. Masters and Inman (2000) have examined fluvial transport of DDT and other legacy pesticides in Upper Newport Bay; they hypothesize that historic agricultural and urban applications of these compounds are the primary upstream sources. No local “hot spots”-specific locations with highly elevated levels of OC pesticides-- were identified.

The State adopted a sediment TMDL and implementation plan in 1999 which called for an overall 50% reduction in sediment loading from San Diego Creek through implementation of a locally developed sediment reduction plan. EPA recommends that the State continue implementation of this sediment reduction plan and monitor to determine whether levels of organochlorine compounds continue to decline. Monitoring should examine not only the levels of organochlorine pollutants in the water column, but also sediment running into tributary streams, sediment moving down San Diego Creek, and sediments in Newport Bay.

Monitoring results show exceedances of EPA and State fish tissue screening values, which indicate the applicable narrative water quality standards are not being met. Specifically, toxaphene exceedances (87%, n=15) of the OEHHA tissue screening value occur only in San Diego Creek (TSM). Tissue exceedances have also occurred for Chlordane (40%), Dieldrin (93%), total DDT (93%), and total PCBs (67%) in San Diego Creek (n= 15 for all, TSM). Similar elevated fish tissue concentrations indicate bioaccumulation for Chlordane, Dieldrin, total DDT and total PCBs in all saltwater bodies of Newport Bay (except for dieldrin in Upper Bay).

We have prioritized sediment quality guidelines over tissue screening values and water column criteria. This decision is based on the following factors:

1. These pollutants are directly associated with sediments (i.e., fine particulate matter); 2. Sediments are the transport mechanism for these organochlorine compounds from freshwaters to salt waters; 3. Limited water column data are available to adequately describe the past or current conditions 4. Attainment of the sediment targets will be protective of the water column criteria and tissue screening values.

Tables 6-5 through 6-8 summarize the existing loads, the estimated loading capacity, and the total allocation for each pollutant with respect to each waterbody. For most pollutant/waterbody combinations, the loading capacity value is less than the existing load and thus the loading capacity determines the TMDL, as seen in Table 6-4. A 10% margin of safety was subtracted from the loading capacity or existing load, whichever is smaller value.

Table 6-5. Summary of San Diego Creek Loadings and TMDL Pollutant Existing Load1 Loading Capacity2 TMDL Margin of Safety (g/year) (g/year) (g/year) (g/year) Chlordane 615.7 314.7 314.7 31.5 Dieldrin 381.8 261.5 261.5 26.2 DDT 3733.8 432.6 432.6 43.3 PCBs 282.1 2226 282.1 28.2 Toxaphene 582.1 8.9 8.9 0.9 1 existing load based on observed data (OCPFRD 1999/00 and SCCWRP 2001a) 2 loading capacity based on sediment targets TMDL is lesser value of existing load or loading capacity; TMDL = Total allocation + MOS

Table 6-6. Summary of Upper Newport Bay Loadings and TMDL Pollutant Existing Load1 Loading Capacity2 TMDL Margin of Safety (g/year) (g/year) (g/year) (g/year) Chlordane 290.7 160.6 160.6 16.1 DDT 1080.2 276.5 276.5 27.7 PCBs 858.7 1528.2 858.7 85.9 1 existing load based on observed data (OCPFRD 1999/00 and SCCWRP 2001a) 2 loading capacity based on sediment targets TMDL is lesser value of existing load or loading capacity; TMDL = Total allocation + MOS

Table 6-7. Summary of Lower Newport Bay Loadings and TMDL Pollutant Existing Load1 Loading Capacity2 TMDL Margin of Safety (g/year) (g/year) (g/year) (g/year) Chlordane 50.2 59.2 50.2 5.0 Dieldrin 5.9 18.6 5.93 0.59 DDT 438.4 101.85 101.8 10.2 PCBs 409.8 562.95 409.8 41.0 1 existing load based on observed data (OCPFRD 1999/00 and SCCWRP 2001a) 2 loading capacity based on sediment targets TMDL is lesser value of existing load or loading capacity; TMDL = Total allocation + MOS

Table 6-8. Summary of Rhine Channel Loadings and TMDL Pollutant Existing Load1 Loading Capacity2 TMDL Margin of Safety (g/year) (g/year) (g/year) (g/year) Chlordane 0.33 1.70 0.33 0.3 Dieldrin 3.76 0.53 0.53 0.05 DDT 5.60 2.92 2.92 0.23 PCBs 70.0 16.2 16.2 1.6 1 existing load based on observed data (OCPFRD 1999/00 and SCCWRP 2001a) 2 loading capacity based on sediment targets TMDL is lesser value of existing load or loading capacity; TMDL = Total allocation + MOS

Table 6-1b Numeric targets for water column concentrations are provided in Table 6-1b based on CTR criteria. These concentrations apply to freshwater bodies (USEPA 2001a); numeric objectives are not available for several of the pollutants in saltwater. We used these targets when modeling the maximum allowable concentrations for water-associated loads from particulate pollutants. (See modeling and analysis section).

Table 6-1b. Freshwater column target values for organochlorine compounds. Pollutant CMC (acute) CCC (chronic) (µ/L) (µ/L) PCBs ---- 0.014 DDT * 1.1 0.001 Chlordane 2.4 0.0043 Dieldrin 0.24 0.056 Toxaphene 0.73 0.0002 * DDT value cited for 4,4’ DDT, but value will apply to one isomer or sum of all isomers detected.

Tables 6-9, 6-10, 6-11, and 6-12 present the allocations for each OC pollutant-waterbody combination. Allocations were assigned for sources to San Diego Creek primarily in proportion to land use area. First, it was assumed that erosion control activities pursuant to the sediment TMDL implementation plan would result in approximately a 50% reduction in OC pollutant runoff from agriculture. We estimate that erosion control practices will result in substantial reduction in OC pollutant loadings associated with eroded sediments (EPA, 1993). The remaining portion (approximately 72%) was allotted to urban runoff.

Table 6-9. Allocations for San Diego Creek Watershed Category Type DDT (including Chlordane Dieldrin PCBs Toxaphene Dicofol) WLA Urban 302.8 220.3 183.4 177.7 6.2 runoff Caltrans 8.7 6.3 5.2 42.3 0.2 Other 34.6 25.2 21.0 5.6 0.7 NPDES permittees Subtotal 346.1 g/yr 251.8 g/yr 209.6 g/yr 225.6 g/yr 7.1 g/yr

LA Ag runoff 8.6 6.2 5.2 5.6 0.2 Undefined* 34.6 25.2 21.0 22.6 0.7 Subtotal 43.2 g/yr 31.4 g/yr 26.2 g/yr 28.2 g/yr 0.9 g/yr

MOS 43.3 g/yr 31.5 g/yr 26.2 g/yr 28.2 g/yr 0.9 g/yr

Total 432.6 g/yr 314.7 g/yr 262.0 g/yr 282.0 g/yr 8.9 g/yr TMDL * undefined = existing sediments + air deposition Total TMDL = WLA + LA + MOS

Table 6-10. Allocations for Upper Newport Bay Category Type DDT (including Chlordane PCBs dicofol) WLA Urban runoff 207.4 120.5 609.7 Caltrans 2.8 1.6 8.6 Other NPDES 2.8 1.6 8.6 permittees Subtotal 212.9 g/yr 123.7 g/yr 626.9 g/yr

LA Ag runoff 2.8 1.6 8.6 Undefined* 33.2 19.3 137.4 Subtotal 35.9 g/yr 20.9 g/yr 146.0 g/yr

MOS 27.7 g/yr 16.1 g/yr 85.9 g/yr

Total TMDL 276.5 g/yr 160.6 g/yr 858.7 g/yr * undefined = existing sediments + air deposition Total TMDL = WLA + LA + MOS

Table 6-11. Allocations for Lower Newport Bay Category Type DDT Chlordane Dieldrin PCBs (including dicofol) WLA Urban runoff 76.3 12.6 4.45 303.3 Caltrans 0 0 0 4.10 Other 000 0 NPDES permittees Subtotal 76.3 g/yr 12.6 g/yr 4.45 g/yr 304.7 g/yr

LA Ag runoff 000 0 Undefined* 15.3 32.6 0.89 61.5 Subtotal 15.3 g/yr 32.6 g/yr 0.89 g/yr

MOS 10.2 g/yr 5.0 g /yr 0.59 g/yr 41.0 g/yr

Total 101.8 g/yr 50.2 g/yr 5.93 g/yr 409.8 g/yr TMDL * undefined = existing sediments + air deposition Total TMDL = WLA + LA + MOS

Table 6-12. Allocations for Rhine Channel Category Type DDT Chlordane Dieldrin PCBs (including dicofol) WLA Urban runoff 0.7 0.1 0.13 4.1 Other 000 0 NPDES permittees Subtotal 0.7 g/yr 0.1 g/yr 0.13 g/yr 4.1 g/yr

Undefined* 1.9 0.21 0.34 10.5 Subtotal 1.9 g/yr 0.21 g/yr 0.34 g/yr 10.5 g/yr

MOS 0.3 g/yr 0.03 g/yr 0.05 g/yr 1.6 g/yr

Total TMDL 2.9 g/yr 0.33 g/yr 0.53 g/yr 16.2 g/yr * undefined = existing sediments + air deposition Total TMDL = WLA + LA + MOS

Metals

Sediment metal concentrations generally increase along the gradient from freshwater to saltwater with maximum levels found in Rhine Channel. Sediment toxicity has been repeatedly observed in sediment and porewaters of Upper and Lower Bay, including Rhine Channel (BPTCP 1997; Bay et al. 2000, SCCWRP 2001a). Porewater is water found within the bottom sediments. Evidence of degraded benthic organisms also exists in these saltwater bodies. The cause of toxicity and benthic degradation is unknown, however a statistical correlation was found between sediment and porewater toxicity to amphipods and sea urchin larvae and elevated copper, lead and zinc sediment concentrations (BPTCP 1997). Cadmium, copper, lead and zinc may bioconcentrate in lower organisms but these metals generally do not bioaccumulate and therefore are not likely to threaten organisms higher in the food chain such as fish-eating birds.

This inverse relationship between flow rate and hardness influences both acute and chronic metals numeric targets. EPA is identifying numeric targets and TMDLs for both chronic and acute conditions. It is appropriate to set TMDLs for chronic conditions in the lower three flow tiers based on an analysis of flow durations.

Table 5-2. Metals Numeric Targets (ug/L) Based on Flow Tiers for San Diego Creek Base Flows Small Flows Medium Flows Large Flows Dissolved (<20 cfs) (21-181 cfs) (182-815 cfs) (>815 cfs) Metal Hardness @ 400 mg/L Hardness @ 322 mg/L Hardness @ 236 mg/L @ 197 mg/L Acute Chronic Acute Chronic Acute Chronic Acute Cd 19.1 6.2 15.1 5.3 10.8 4.2 8.9 Cu 50 29.3 40 24.3 30.2 18.7 25.5 Pb 281 10.9 224 8.8 162 6.3 134 Zn 379 382 316 318 243 244 208 Note: Actual ambient hardness must be determined for each monitoring sample regardless of which flow condition exists.

Table 5-3. Numeric Targets for Metals in Newport Bay Dissolved saltwater Dissolved saltwater Alternate target Metal Acute target Chronic target In saltwater sediments (µg/L) (µg/L) (mg/kg dry) Cd* 42 9.3 0.67 Cu 4.8 3.1 18.7 Pb 210 8.1 30.2 Zn 90 81 124 Source: CTR values for dissolved metals in saltwaters: NOAA TEL values for sediments) *Cd value applies to Upper Newport Bay only

Total metals loading estimates in Table 5-4 have also been adjusted based on these results to report the approximate load believed to be associated with anthropogenic activities. Several other sources of metals exist in the watershed: runoff from open spaces, nursery and agricultural applications, groundwater dewatering and cleanup, and atmospheric deposition. Using mass loading calculations presented in that TMDL and local data concerning boats in Newport Bay, passive leaching from recreational boats and underwater hull cleaning are estimated to comprise the most significant sources (>80%) for dissolved Cu into Lower Bay, Rhine Channel and, to some extent, Upper Bay. Porewater concentrations measured in Lower Bay (not including Rhine Channel) suggest that Cu levels are elevated enough to create potentially negative impacts (Bight ’98). Levels for the other metals are within the range of concentrations observed in ambient seawater and well below the dissolved saltwater numeric targets.

Wet weather conditions, which may occur at any time of the year, yield medium and large flows and a range of hardness values. High flows are more likely to produce both low hardness and higher metal levels; these conditions are the biggest threat to aquatic organisms in San Diego Creek and its tributaries. For Newport Bay, the TMDLs address long term metals accumulations which are associated with metals-caused sediment toxicity measured in the Bay. Therefore, there is no single season or critical season of greatest concern for metals loadings and effects in Newport Bay. The saltwater allocations apply during all seasons, regardless of flow.

For both San Diego Creek and Newport Bay, the approach of setting concentration based TMDLs and allocations based on chronic and acute targets helps address and mitigate any short term effect associated with brief periods of high metals loading

Table 5-4. Estimates of Total metal loadings from two freshwater inputs to Upper Bay Metal Site 1998 water Adjusted* 1999 water- Adjusted* year 1998 results year 1999 results (OCPFRD) (Man-made) (OCPFRD) (Man-made) Total load Total load Total load Total load (lbs.) (lbs.) (lbs.) (lbs.) Cu San Diego Creek 15, 087 6,261 1,643 682 Santa Ana -Delhi 1,643 682 185 77 Pb San Diego Creek 10,385 3,977 449 172 Santa Ana -Delhi 1,297 497 124 47 Zn San Diego Creek 63,021 20,985 3,784 1,260 Santa Ana -Delhi 7,031 2,341 805 286 Source: 1998 and 1999 water-year results from OCPFRD 2000 * Adjustments made from man-made approximations reported by Schiff and Tiefenthaler 2000

Table 5-5a. Mass-based dissolved metal loading capacity for Newport Bay Dissolved Metal Upper and Lower Bay Including Rhine Channel Dissolved Load (lbs/yr) Cd 14,753* Cu 11,646 Pb 27,136 Zn 285, 340 * Cd load applies to Upper Bay only, where volume of Upper Bay is approximately 40% of the total volume of Newport Bay.

Table 5.5b Concentration-based dissolved metal loading capacity for Newport Bay Dissolved saltwater Dissolved saltwater Metal Acute loading capacity Chronic loading capacity (µg/L) (g/L) Cd* 42 9.3 Cu 4.8 3.1 Pb 210 8.1 Zn 90 81

EPA implementation recommendations

• Investigate historic PCB spills • Implement sediment TMDL • Monitor for OCs loading in water column, sediments and tissue in San Diego Creek and tributaries as well as the bay • Improve understanding of sources and effects • Condition sediment removal projects in the bay such that sediment disturbance is minimized • Develop a coordinated monitoring program (RMP) • Develop appropriate implementation plan

Metals TMDL implementation recommendations including mercury & chromium

Metals loading in the watershed is associated primarily with ongoing runoff from urban and undeveloped areas, and aquatic sediments containing previously discharged metals.

EPA recommends five areas of action to address metals loading in the watershed.

1. Metals levels in the Rhine Channel area are estimated to be substantially higher than in other areas of the watershed. EPA recommends aggressive action to complete and implement the contaminated sediment remediation plan initiated by the State and Regional Boards in 1997. One potential ongoing source of concern with respect to chromium loading is the Newport Plating facility. EPA recommends that the State further assess this facility and, if necessary, carry out discharge controls or remedial actions necessary to address any ongoing loadings.

2. The source analysis indicated that copper leaching from boat paints is probably a significant source of copper loading to the Bay. In coordination with marina and boatyard operators, other Regional Boards, the State Board, and EPA, the Santa Ana Regional Board should develop specific actions to reduce the use of copper-containing boat paints or their leaching to water bodies through use of additional boat storage and maintenance practices.

3. The Regional Board should work with the stormwater discharge permittees to further assess the potential effectiveness of available management practices to reduce metals loading in discharges of urban runoff under high and low flows.

4. EPA recommends that the State continue implementation of this (1999) sediment reduction plan and monitor to determine whether both total and dissolved metals loading levels decline over time.

5. EPA believes it may be reasonable to consider whether newly emerging criteria calculation methods would result in protective but easier-to-implement standards.

Additional strategies for metals TMDLs • Urban runoff BMPs for parking lots, roads • Commercial BMPs • Boat paint restrictions

Chromium and Mercury

TMDLs are being established for chromium (Cr) and mercury (Hg) only for the Rhine Channel area of Lower Newport Bay. Two targets are provided for each chemical, one for sediment and one for tissue levels. The primary target value (sediment) is for TMDL development, whereas the alternate target (tissue) is designed to provide another means of assessing desired water quality conditions of Rhine Channel.

This methylmercury target is designed to protect human health, yet it will also be effective at reducing impacts to wildlife predators due to bioaccumulation. Probable sources of chromium include the heavily contaminated sediments existing in Rhine Channel, previous discharges by metal plating facilities near Rhine Channel, historic deposits in the San Diego Creek watershed and atmospheric deposition. The Regional Board has documented two previous investigations of metals contamination at Newport Plating Company. Chromium may also be leaching from treated wood pylons in marine areas. The heavily contaminated sediments in Rhine Channel are most likely associated with historic discharges from industrial facilities around Rhine Channel, and these legacy sources are likely to be the largest current sources of chromium. Most likely, existing sediments are the largest sources of mercury in Rhine Channel. Available evidence for all of Newport Bay suggests that mercury levels in the rest of Newport Bay are not elevated.

Table 7-1. Numeric Targets for Chromium and Mercury in Rhine Channel Waterbody Analyte Sediment target Alternate (mg/kg dry) Fish tissue target (mg/kg/wet) Rhine Channel Chromium (Cr) 52 0.2 Rhine Channel Mercury (Hg) 0.13 0.3* * Mercury tissue is interpreted as 0.3 mg/kg/wet methylmercury (EPA proposed criteria and USFWS 2000)

The wasteload and load allocations (Table 7-4) were calculated based principally on best professional judgment. Most of the available loads were assigned to sediments already in Rhine Channel, which are by the far the largest source. These allocations to existing sediments reflect substantial reductions in sediment loads from in-Channel sources based on the expected effectiveness of remedial actions identified in the 1997 remedial action plan. The remaining available load was allocated roughly in proportion to the land areas associated with the remaining source categories after allocating 5% of available loads for undefined sources. Further investigation of Newport Plating facility may warrant revision of such a high allocation to sediments in Rhine Channel for chromium.

Table 7-4. Rhine Channel Wasteload and Load Allocations (kg/yr) and % of total loads Mercury (Hg) Chromium (Cr) Wasteload Allocations: Stormwater 0.0171 (19%) 5.66 (19%) Caltrans 0.0027 (3%) 0.89 (3%) Boat yards 0 0 Other NPDES permittees 0.0027 (3%) 0.89 (3%)

Load Allocations: Existing sediment 0.063 (70%) 20.85 (70%) Undefined sources: air deposition, 0.0045 (5%) 1.49 (5%) ambient seawater

Margin of Safety 0.10 3.30 TMDL 0.1 kg/yr 33.1 kg/yr TMDL = WLA + LA + MOS

Implementation of TMDLs

As discussed in Section 1, the Clean Water Act creates federal regulatory jurisdiction only over point sources. Therefore, the direct implementation effect of EPA’s TMDLs is that when NPDES permits for point source discharges are issued or revised for discharges to waters in the watershed, the State is required to ensure that the permits contain effluent limitations necessary to be consistent with the wasteload allocations (WLAs) contained in the TMDLs (40 CFR 122.44(d)). Permit modification may occur when existing permits are reopened or reissued, or when a new discharge source seeks a permit. NPDES permit holders should contact the Regional Board to discuss how and when action will be taken to implement applicable WLAs.

The State has discretion to determine how the point source permit provisions will be made consistent with applicable WLAs. Depending upon the situation and the level of precision in the WLA, it may be appropriate to:

ƒ incorporate numeric effluent limitations for the pollutant(s) of concern in the permit, ƒ identify best management practices and associated pollutant control effectiveness which demonstrate that the WLAs will be attained, and/or ƒ require the discharger to submit a WLA compliance plan and schedule which demonstrates how the WLA will be implemented.

In addition to addressing WLA implementation through the NPDES permitting process, the State should work with local stakeholders to identify specific actions necessary to carry out load allocations identified in the TMDLs. These actions may be based on voluntary or regulatory approaches. We note that CWA Section 319(h) nonpoint source implementation grant funds may be available to assist in implementing controls necessary to implement load allocations. Section 319(h) projects designed to implement TMDLs currently receive priority for funding. Landowners or land managers interested in seeking Section 319(h) funding assistance should contact the Regional Board staff for more information concerning the State’s grant funding process.

Fecal coliform & pathogens TMDL http://www.ocwatersheds.com/watersheds/tmdls_fecal_coliform_intro.asp

Table 5-9f: Total Maximum Daily Load, Waste Load Allocations and Load Allocations for Fecal Coliform in Newport Bay Total Waste Load Load Allocations for Load Allocations Waste Load Maximum Allocations for fecal fecal coliform in for fecal Allocations for Daily Load for coliform in urban agricultural runoff, coliform from vessel waste fecal coliform in Newport Bay runoff, including including natural sources stormwater, stormwater, in all discharges discharges to discharges to to Newport Bay Newport Bay Newport Bay As soon as possible but no later than December 30, 2013 In Effect In Effect 5-Sample/30- 5-Sample/30-days 5-Sample/30-days 5-Sample/30-days 0 MPN/100 ml days Geometric Geometric Mean less Geometric Mean less than Geometric Mean No discharge Mean less than than 200 200 organisms/100ml and less than 200 200 organisms/100ml and not not more than 10% of the organisms/100ml organisms/100ml more than 10% of the samples exceed 400 and not more than and not more samples exceed 400 organisms/100 ml for any 10% of the samples than 10% of the organisms/100 ml for 30-day period exceed 400 samples exceed any 30-day period organisms/100 ml 400 for any 30-day organisms/100 period ml for any 30- day period As soon as possible but no later than December 30, 2019 In Effect Monthly Median Monthly Median less Monthly Median less than Monthly Median 0 MPN/100 ml less than 14 than 14 MPN/100 ml and 14 MPN/100 ml and not less than 14 No discharge MPN/100 ml and not more than 10% of the more than 10% of the MPN/100 ml and not not more than samples exceed 43 samples exceed 43 more than 10% of 10% of the MPN/100 ml MPN/100 ml the samples exceed samples exceed 43 MPN/100 ml 43 MPN/100 ml

Table 5-9f summarizes the TMDL, Waste Load Allocations (WLAs) for point sources of fecal coliform inputs and Load Allocations (LAs) for nonpoint source inputs. As shown, the TMDL, WLAs and LAs are established to assure compliance with water contact recreation standards no later than December 30, 2014 and with shellfish standards no later than December 30, 2019. WLAs are specified for vessel waste and urban runoff, including stormwater, the quality of which is regulated under a County-wide NPDES permit issued by the Regional Board. This runoff is thus regulated as a point source, even though it is diffuse in origin. LAs are specified for fecal coliform inputs from agricultural runoff, including stormwater, and natural sources. The TMDL is to be adjusted, as appropriate, based upon completion of the studies contained in Table 5-9g. (2000) Upon completion of these studies, an updated TMDL report will be prepared summarizing the results of the studies and making recommendations regarding implementation of the TMDL. The results of the studies may lead to recommendations for changes to the TMDL specified in Table 5-9f to assure compliance with existing Basin Plan standards (objectives and beneficial uses). The study results may also lead to recommendations for changes to the Basin Plan objectives and/or beneficial uses. If such standards changes are approved through the Basin Plan amendment process, then appropriate changes to the TMDL would be required to assure attainment of the revised standards. Revision of the TMDL, if appropriate, would also be considered through the Basin Plan amendment process.

Data collected by the OCHCA demonstrate that tributary inflows, composed of urban and agricultural runoff, including stormwater, are the principal sources of coliform input to the Bay. Coliform has diverse origins, including: manure fertilizers which may be applied to agricultural crops and to commercial and residential landscaping; the fecal wastes of humans, household pets and wildlife; and other sources. Special investigations by OCHCA have demonstrated that food wastes are a significant source of coliform. Many restaurants wash down equipment and floor mats into storm drains tributary to the Bay and may improperly dispose of food waste such that it eventually washes into the Bay. Another source of bacterial input to the Bay is the discharge of vessel sanitary wastes. Newport Bay has been designated a no-discharge harbor for vessel sanitary wastes since 1976. Despite this prohibition, discharges of these wastes have continued to occur. Since these wastes are of human origin, they pose a potentially significant public health threat. As noted, the fecal waste of wildlife, including waterfowl that inhabit the Bay and its environs, is a source of coliform input.

The Regional Board is committed to the review of this TMDL every three years or more frequently if warranted by these or other studies. The County of Orange, the Cities of Tustin, Irvine, Costa Mesa, Santa Ana, Lake Forest, and Newport Beach, The and the Irvine Ranch Water District have undertaken to prepare a health risk assessment for Newport Bay for water contact recreation and shellfish harvesting beneficial uses. This study will evaluate whether exceedances of fecal coliform objectives correlates with actual impairment of beneficial uses and may recommend revisions to the Basin Plan objectives and/or beneficial use designations. Because this study is in progress, it is not required by this TMDL implementation plan, but will be considered in conjunction with the studies required by the implementation plan.

Strategies for pathogens management

• Improved enforcement of existing boat waste restrictions • More pet waste bag stations & receptacles • Updated sewer lines • Enforcement of restaurant wash water disposal • Restrictions on manure use

References

Amendment to the Santa Ana Region Basin Plan. Attachment to Resolution No. 99-10. Chapter 5 Implementation Plan, Discussion of Newport Bay Watershed, Bacterial Contamination

California Regional Water Quality Control Board, Santa Ana Region. 1995. Water Quality Control Plan, Basin. Basin Plan Total Maximum Daily Load for Sediment in the Newport Bay/San Diego Creek Watershed, Attachment -Resolution No. 98-101.

County of Orange, California. Upper Newport Bay/San Diego Creek Watershed Sediment TMDL, 2005-06 Annual Report.

County of Orange, California. Upper Newport Bay/San Diego Creek Watershed Sediment TMDL, 2006-07 Annual Report.

Resolution Amending the Water Quality Control Plan for the Santa Ana River Basin to Incorporate a Nutrient TMDL for the Newport Bay/San Diego Creek Watershed. Attachment to Resolution No. 98-9, as amended by Resolution No. 98-100

U.S. Environmental Protection Agency Region 9. June 14, 2002. Total Maximum Daily Loads For Toxic Pollutants, San Diego Creek and Newport Bay, California. http://www.epa.gov/region09/water/tmdl/final.html

Websites:

TMDL (Total Maximum Daily Load) Documents

http://www.swrcb.ca.gov/rwqcb8/html/tmdls.html http://www.ocwatersheds.com/watersheds/tmdls.asp http://www.epa.gov/region09/water/tmdl/nbay/tsde0602.pdf

Basin Plans (Water Quality Control Plans), NPDES stormwater permits http://www.ocwatersheds.com/StormWater/documents_Basin_Plans.asp

Rhine Channel Sediment Remediation Feasibility Study and Alternatives Evaluation, Newport Bay, California, 2006 http://coastkeeper.org/content/documents/RhineChannelFSFinalDraft01-13-06- Introduction.pdf

Sediment monitoring report with graphics and lists of retention and detention http://www.ocwatersheds.com/watersheds/pdfs/sediment_tmdl/San_Diego_Creek_Sediment _TMDL_2002_report.pdf

Santa Ana RWQCB Watershed Management Initiative (WMI) http://www.swrcb.ca.gov/rwqcb8/water_issues/programs/wmi/index.shtml

Regional Board watershed coordinator for the Newport Bay Watershed: Doug Shibberu: (909) 782-7959.

Stormwater

Orange County Stormwater Drainage Area Management Plan (DAMP) http://www.ocwatersheds.com/StormWater/documents_damp_toc.asp

References for non-point source (stormwater) programs: http://www.ocwatersheds.com/StormWater/swp_documents_intro.asp