NPDES WASTEWATER DISCHARGE PERMIT EVALUATION
Department of Environmental Quality Eastern Region - Bend Office 475 NE Bellevue, Suite 110, Bend, OR 97701 Telephone: (541) 388-6146
PERMITTEE: Meadows Utilities LLC P.O. Box 470 Mt. Hood, OR 97041 File Number: 58827 Permit Number: 100681 SOURCE LOCATION: Mt. Hood Meadows Ski Area, Hwy 35, Hood River County SOURCE CONTACT: Mr. Steve Warila Telephone Number: (503) 337-2222, ext. 206 PERMIT WRITER: Paul DeVito Telephone Number: (541)633-2029
PROPOSED ACTION: Renewal of a National Pollutant Discharge Elimination System (NPDES) wastewater discharge permit SOURCE CATEGORY: Minor Domestic
TREATMENT SYSTEM CLASS: Level R
COLLECTION SYSTEM CLASS: Level I
PERMIT APPLICATION DATE: November 30, 2007
PERMIT APPLICATION NUMBER: 973739
BACKGROUND Introduction Meadows Utilities LLC operates a wastewater treatment facility located at the Mt. Hood Meadows Ski Area. Wastewater is treated and discharged to East Fork Hood River in accordance with National Pollutant Discharge Elimination System (NPDES) Permit number 100681. The Permit for the facility was issued on December 19,2003 and expires on November 30,2008.
This permit is being renewed early under the new watershed approach. Under this approach, all sources in a watershed are being renewed hi the same year. This approach allows the Department to consider water quality issues comprehensively by basin, which is a more holistic approach to protecting waters of the state. The sources in the Mid- Columbia Hood Watershed are being renewed in 2007. The Department received a renewal application on November 30,2007. A renewal permit is necessary to discharge to state waters pursuant to provisions of Oregon Revised Statutes (ORS) 468B.050 and the Federal Clean Water Act. The Department proposes to renew the permit.
Facility Description Meadows Utilities LLC owns and operates a wastewater collection system and activated sludge sewage treatment facility under this permit. The ski resort includes two day lodges that contain six food service establishments, laundry, a day care center, three main restroom areas, offices and rental, sales and maintenance shops. No overnight facilities are currently included at the ski resort.
Wastewater from the ski resort is processed through a sewage grinder and flows into two of three 65,000 gallon Activated Sludge - Sequencing Batch Reactors (SBR). The third SBR has not been needed and is currently used to Meadows Utilities LLC Evaluation Report Page 2 store and aerate excess solids. The wastewater is then pumped to a 25,000 gallon holding chamber, filtered, disinfected with UV light, and discharged to the East Fork of the Hood River.
Biosolids Management and Utilization The permittee operates under a Department approved Biosolids Management Plan to ensure compliance with the federal biosolids regulations (40 CFR Part 503). The permittee currently stabilizes solids from the treatment plant by the addition of lime.
During the summer months, sludge from the bottom of the reactor basins is wasted to the unused SBR 1 and allowed settling. Supernatant from the wasting process is pumped out by a small effluent sump pump into SBR2 for treatment. The remaining solids in SBR1 are stabilized by the addition of lime to meet pathogen reduction requirements. pH is raised above 12 for two hours and maintained above 11.5 for 24 hours. In August, sludge is removed from storage vessels by a DEQ licensed sewage disposal operator for transportation to a wastewater treatment or disposal facility or for land application.
This permit requires monthly reporting of the methods used to comply with vector attraction and pathogen reduction requirements. It also requires the submittal of an annual summary.
Pretreatment The permittee does not have a formal pretreatment program, nor is one required for this source.
Pollutants Discharged The current permit allows Meadows Utilities LLC to discharge treated effluent from the wastewater treatment plant year round. The current permit sets limits on the following pollutants: Five-day Biochemical Oxygen Demand (BOD5), Total Suspended Solids (TSS), and Fecal Coliform (FC) bacteria. The discharge is also regulated for pH, pollutant removal efficiency, and temperature. In addition to the current limits, the proposed permit reinstates limits on flow.
Outfalls Treated wastewater is discharged to East Fork Hood River (Outfall 001). The previous permit provided for the construction of seepage beds (Outfall 002) to be used during the summer when the river temperature exceeds the water quality criteria. However, the seepage beds were never constructed. This system serves a ski area. As would be expected with such a facility, summertime flows are quite low. When the river temperature has exceeded water quality criteria for the protection of resident trout, the permittee has been able to completely stop discharging to the East Fork Hood River. The effluent is stored in the 25,000 gallon holding chamber until the river temperature falls below the water quality criteria. Continuous temperature monitors in the stream ensure that the plant does not discharge when the water quality criteria in the stream is exceeded. Discharge automatically ceases when temperatures rise above 55 degrees farenheit.
The Department proposes to keep the provision for the seepage beds (Outfall 002) in the permit as an option for the permittee to construct if and when necessary.
Receiving Streams/Impact The designated beneficial uses of the receiving stream are: public and private domestic water supply, industrial water supply, irrigation, livestock watering, resident fish and aquatic life, wildlife and hunting, fishing, boating, water contact recreation, aesthetic quality and hydro power.
Stormwater Stormwater is not addressed in this permit. General NPDES permits for stormwater are not required for facilities with a design flow of less than 1 MGD.
Compliance History This facility was last inspected August 22,2007 and was operating in compliance with the permit.
The monitoring reports for this facility were reviewed for the period since the current permit was issued, including any actions taken relating to effluent violations. The permit compliance conditions were reviewed and all Meadows Utilities LLC Evaluation Report Page 3 inspection reports for the same period were reviewed. No violations of the permit were documented during the period when the current permit was in effect. Therefore, this facility has operated in compliance with the current permit.
PERMIT DISCUSSION Face Page The permittee is authorized to construct, install, modify, or operate a wastewater collection, treatment, control and disposal system. The' proposed permit will allow continued discharge of treated effluent to the East Fork Hood River or to the approved seepage bed within limits set by Schedule A and the following schedules. All other discharges are prohibited.
Schedule A - Waste Discharge limitations BOD and TSS concentration limits Proposed biochemical oxygen demand (BOD5) and suspended solids (TSS) effluent concentration and mass load limits for the dry weather and wet weather periods will remain the same as in the current permit.
Meadows Utilities LLC upgraded the Mount Hood Meadows wastewater treatment facility in 1988. During the design process, the design engineer met with DEQ to determine what requirements the facility would need to meet, hi a letter dated April 19, 1988, DEQ informed Mt. Hood Meadows that the requirements of the Hood Basin standard would be met during November 1 - April 30 with an effluent concentration of 20 mg/L for both BOD and TSS and a dilution factor of 20:1 at a monthly average effluent flow rate of 0.0375 MGD. Similarly, the letter indicated that the requirements of the standard would be met during May 1 - October 31 when the dilution factor is only 10:1 with an effluent concentration of 10 mg/L. During this timeframe, when the dilution factor is 20:1, the requirements could also be met by an effluent concentration of 20 mg/L, provided the monthly average flow rate was reduced to 0.01875 MGD. The minimum design criteria for the Hood Basin has not changed since this letter was signed.
Therefore, the Department proposes to renew the permit and existing limits, with the addition of these flow rate limitations.. A review of recent monitoring data indicates the Utility should generally be able to comply with the permit limits.
BOD and TSS mass limits
Summer BOD5 & TSS Mass Limits (a) monthly avg. = 0.0375 MGD x 10 mg/L x 3.785 L/gal x 1/453,592 lb/mg = 3.19 lbs/day (b) weekly avg. = 3.19 lbs/day monthly avg. x 1.5 = 4.78 lbs/day (c) daily max = 3.19 lbs/day monthly avg, x 2.0 = 6.38 lbs/day.
Winter BOD5 & TSS Mass Limits (a) monthly avg. - 0.0375 MGD x 20 mg/L x 3.785 L/gal x 1/453,592 lb/mg = 6.25 lbs/day (b) weekly avg. = 6.25 monthly avg. x 1.5 = 9.37 lbs/day (c) daily max = 6.25 lbs/day monthly avg. x 2.0 = 12.5 lbs/day.
BOD and TSS Percent Removal Efficiency A minimum level of percent removal for BOD5 and TSS for municipal dischargers is required by the Code of Federal Regulations (CFR) secondary treatment standards (40 CFR, Part 133). An 85 percent removal efficiency limit is included in the proposed permit to comply with federal requirements. An examination of the DMR data indicates the permittee will have no difficulty meeting the limit with the current facilities. pH The Hood Basin Water Quality Standard for pH is found in OAR 340-041-0165(l)(a). The allowed range is 6.5 to 8.5 standard units. The proposed permit limits pH of the effluent to the range 6.0 to 9.0. This limit is based on Federal wastewater treatment guidelines for sewage treatment facilities, and is applied to the majority of NPDES permittees in the state. Although the water quality standard for pH does not have to be met within the permittee's mixing zone, the Meadows Utilities LLC Evaluation Report Page 4
Department expects that mixing with ambient water within the mixing zone will ensure that pH at the edge of the mixing zone will meet the standard.
The permittee has submitted data detailing the pH and temperature of the discharge and the temperature of the receiving stream. By making assumptions for stream and effluent alkalinity, and assuming a conservative range for ambient pH in the East Fork Hood River, a reasonable potential analysis (RPA) can be conducted. The RPA (Appendix 1) shows that limits of 6.0-9.0 s.u. will ensure that the water quality standard of 6.5-8.5 s.u. will be met at the mixing zone boundary. The proposed pH limits remain unchanged from the current permit, and are protective of the water quality standard.
Bacteria The proposed permit limits are based on the E. coli standard contained in OAR 340-041-0009(5). The proposed limits are a monthly geometric mean of 126 __. coli per 100 mL, with no single sample exceeding 406 E. coli per 100 mL. If a single sample exceeds 406 E. coli per 100 mL, then the permittee may take five consecutive re- samples. If the log mean of the five re-samples is less than or equal to 126, a violation is not triggered. The re sampling must be taken at four hour intervals beginning within 28 hours after the original sample was taken.
The proposed limits are taken directly from the Oregon bacteria rule which is found in OAR 340-041-0009. This rule establishes numeric in-stream water quality standards (OAR 340-041-0009(1)), establishes a prohibition against discharging raw sewage, establishes effluent limitations and the methodology for establishing a violation (OAR 340-041-0009(5)). Regarding the general condition 6 found in Section B of Schedule F in this permit which prohibits overflows from wastewater conveyance systems, the Environmental Quality Commission (EQC) recognizes that it is impossible to design and construct a conveyance system that will prevent overflows under all storm conditions. The applicant is not seeking permit coverage for overflows and the permit does not authorize such discharges. The State of Oregon has determined that all wastewater conveyance systems should be designed to transport storm events up to a specific size to the treatment facility. Therefore, in exercising its enforcement discretion regarding Sanitaiy Sewer Overflows, the Department will consider the following:
(1) Whether the permittee has conveyance and treatment facilities adequate to prevent overflows except during a storm event greater than the one-in-five-year, 24-hour duration storm from November 1 through May 21 and except during a storm event greater than the one-in-ten-year, 24-hour duration storm from May 22 through October 31. In addition, DEQ will also consider using enforcement discretion for overflows that occur during a storm event less than the one-in-five-year, 24-hour duration storm from November 1 through May 21 if the permittee had separate sanitaiy and storm sewers on January 10, 1996, had experienced sanitary sewer overflows due to inflow and infiltration problems, and has submitted an acceptable plan to the Department to address these sanitary sewer overflows by January 1,2010;
(2) Whether the permittee has provided the highest and best practicable treatment and/or control of wastes, activities, and flows and has properly operated the conveyance and treatment facilities;
(3) Whether the permittee has minimized the potential environmental and public health impacts from the overflow; and
(4) Whether the permittee has properly maintained the capacity of the conveyance system.
DEQ will review the permittee's determination of the one-in-five-year, 24-hour duration winter storm and the one- in-ten year, 24-hour duration summer storm as described above in the permit holder's facilities plan. In the event that a permit holder reports an overflow event associated with a storm event and DEQ does not have information from the permit holder sufficient to determine whether or not the storm event exceeds storm events as specified in OAR 340-041 -0009(6) & (7), DEQ will perforin the determination using the information contained in Figure 26 of the 1973 NOAA Atlas 2 entitled "Precipitation-Frequency Atlas of the Western United States, Volume X - Oregon". This figure is entitled "Isopluvials of 5-yr 24-hr precipitation in tenths of an inch". The Atlas can be obtained on line at http://Iidsc.nws.noaa.gov/hdsc/pfds/other/or_pfds.html, however the file is very large. A scanned version of Figure 26 is available at: http://www.wrcc.dri.edu/pcpnfreq/or5y24.gif. DEQ will compare the Meadows Utilities LLC Evaluation Report Page 5 information in this figure with rainfall data available from the National Weather Service, or other source as necessary.
Total Chlorine Residual The treatment facility uses ultra-violet light to disinfect the treated wastewater. No chlorine or chlorine compounds may be used for disinfection purposes and no chlorine residual will be allowed in the effluent due to chlorine used for maintenance purposes.
Ammonia The Department performed a RPA for ammonia to determine whether the effluent discharge has the potential to cause toxicity at the mixing zone or zone of immediate dilution boundaries. The results of the RPA (Appendix 2) show that there is no potential for ammonia toxicity. Therefore, no ammonia limits have been proposed for this permit.
Temperature The Department proposes to maintain the temperature limits at the current levels.
On December 26,2001, the Director of Oregon DEQ issued a total maximum daily load (TMDL) for temperature for the Western Hood River sub basin and submitted it to the US Environmental Protection Agency (EPA) for approval. On January 30,2002, EPA approved the TMDL for temperature for the Western Hood River sub-basin. The permittee discharges to the East Fork Hood River, above the Sahalie Falls within this subbasin. Resident fish only are present in this area; anadromous fish do not migrate or spawn upstream of the falls.
According to the 2001 TMDL, the WLAs for the Utility essentially prohibit any measurable increase (>0.25°F) above 55°F [12.8°C] during the spawning season (January 1-August31 of each year) or above 64°F [17.8°C] during the remainder of the year. It is unlikely that the rearing criterion of 64°F will ever be exceeded.
The proposed permit maintains a prohibition on discharging to the East Fork Hood River when the river temperature exceeds 55T during the spawning period or 64°F during the rearing period. During these times, the permittee must either refrain from discharging or discharge to the seepage basin (Outfall 002). River temperature is to be measured at the downstream edge of the mixing zone, which ensures that discharge will not cause an exceedance of either of the criteria. In addition, the permit establishes a maximum effluent temperature limit at Outfall 001 of 68°F.
The following graph shows temperature data taken from DMRs submitted by the Utility. Temperature monitoring was conducted at the downstream edge of the mixing zone. The graph illustrates temperature in the East Fork Hood River and temperature of Mt. Hood Meadow's discharge in 2005 and 2006. Meadows Utilities LLC Evaluation Report Page 6
Mt. Hood Meadows Temperature Data
MHM Discharge 7-day A\g.
0) Slream L_ D Temperatu re L_ o Q. Stream Temp E Discharge Criterion
20.0 C$D ffo rSl & s> & -IO ^ A ,^ ,/ j» ^ / / / ,/ XT 4 $ <$ y /* / Date
The data shows that during the summer months, the East Fork Hood River approaches and exceeds the temperature criterion for resident fish spawning near the permittee's outfall. During this time that the spawning criterion is exceeded, the Utility will not be permitted to discharge to the river.
Using the following equation:
Ts'=(TE + Ts(D-l))/p
Where Ts' = temperature in stream after mixing TE= effluent temperature D — dilution at the edge of the mixing zone = 67 (based on a 1998 study)
Ts= upstream temperature
If Ts = resident species spawning criterion of 55°F, and TE= max. allowed effluent temperature of 68°F:
Ts'-(68+ 55 (67-1))/67 = 3698/67 = 55.19°F
If Ts = resident species rearing criterion of 64°F, and TE= max. allowed effluent temperature of 68°F:
Ts' = (68 + 64 (67-1)) / 67 - 4292/67 - 64.06 °F Thus, with the proposed temperature limits, there is no potential for the Utility to cause the applicable temperature criterion to be exceeded by more than 0.25 QF at any time. The proposed limits also ensure that absolutely no heat load will be added to the river when in-stream temperatures reach 55°F during spawning periods and 64°F during rearing periods due to the cessation of discharge under these conditions. This complies with and is in fact more restrictivetha n the TMDL for the Western Hood Sub-basin. These limits are also more restrictive than the current temperature standard. Meadows Utilities LLC Evaluation Report Page 7
Thermal Plume Criteria Recent revisions to the Department's water quality standards include temperature thermal plume limitations in OAR 340-041-0053(2)(d). This section of the rules contains criteria to prevent potential adverse impacts that may result from thermal plumes. Note that the temperature thermal plume limitations that the Department has adopted are similar to the recommendations in the April 2003 EPA Region X Temperature guidance.
The criteria as they apply to Mount Hood Meadows STP are discussed below:
• OAR 340-041-0053(2)(d)(A): Impairment of an active salmonid spawning area where spawning redds are located or likely to be located. This adverse effect is prevented or minimized by limiting potential fish exposure to temperatures of 13 degrees Celsius (55.4 Fahrenheit) or more for salmon and steelhead, and 9 degrees Celsius (48 degrees Fahrenheit) or more for bull trout Mount Hood Meadows STP Discharge: The upper-most reach of the East Fork Hood River does not support the spawning and rearing of anadromous salmon, steelhead, or bull trout. However, it does support the spawning of resident species between the dates of January 1 to August 31 (OAR 340-041 160B; Western Hood Basin TMDL 2001). During this time, the Utility is prohibited from discharging to the East Fork Hood River when the temperature in the river exceeds 55°C. Thus, the discharge is not expected to cause an impairment of active spawning areas.
• OAR S40-041-0053(2)(d)(B): Acute impairment or instantaneous lethality is prevented or minimized by limiting potential fish exposure to temperatures of 32°C or more to less than 2 seconds. Mount Hood Meadows STP Discharge: The Utility is prohibited from discharging effluent greater than 68°F (20°C). Thus, the discharge is not expected to cause an acute impairment or instantaneous lethality.
• OAR 340-041-0053(2)(d)(C): Thermal shock caused by a sudden increase in water temperature is prevented or minimized by limiting potential fish exposure to temperatures of 25°C or more to less than 5% of the cross-section of 100% of the 7Q10 flow of the waterbody. Mount Hood Meadows STP Discharge: The Utility is prohibited from discharging effluent greater than 68°F (20°C). Thus, the discharge is not expected to cause thermal shock.
• OAR 340-041-0053(2)(d)(D): Unless ambient temperature is 21°C or greater, migration blockage is prevented or minimized by limiting potential fish exposure to temperatures of 21°C or more to less than 25% of the cross-section of 100% of the 7Q10 flow of the waterbody. Mount Hood Meadows STP Discharge: The Utility is prohibited from discharging effluent greater than 68°F (20°C). Thus, the discharge is not expected to cause migration blockage.
Thus, the analysis indicates that the discharge from Mount Hood Meadows STP meets the temperature thermal plume limitations in OAR 340-041-0053(2)(d).
Turbidity The previous NPDES permit did not require monitoring for turbidity. Therefore, the Department does not have sufficient data to run a reasonable potential analysis (RPA) or set possible permit limits. Turbidity monitoring has been included in the proposed permit. Turbidity monitoring must be conducted in both the effluent and in the East Fork Hood River upstream of the outfall and recorded on the monthly Discharge Monitoring Reports (DMR). This data will be used to run an RPA during the next permit cycle.
Groundwater The proposed seepage bed would be placed in an area where the shallow groundwater is discharging to the East Fork Hood River. The area between the seepage bed and the river would be part of the ski area lease property. The Department's primary concern in this type of situation would be the impact of the effluent on the water quality of the river. However, in the permittee's case the treated effluent being discharged to the seepage bed would still be required Meadows Utilities LLC Evaluation Report Page 8 to meet the standards for a direct discharge to the river. Therefore, the Department has determined that the discharge to a seepage bed will not have a likely adverse impact on either groundwater or surface water quality.
Mixing Zone and Zone of Immediate Dilution The regulatory mixing zone is that portion of the East Fork Hood River starting at the outfall and extending downstream 100 feet. Based on comments received during the public review period, the Department has added a width limitation to the mixing zone. The final permit will state that the width of the mixing zone shall not exceed 50% of the river width. The Zone of Immediate Dilution (ZID) shall not exceed 10 percent of the defined mixing zone.
The Department believes that the beneficial uses of the receiving stream will not be affected by the discharge and this mixing zone and that the defined mixing zone meets the criteria in the rule.
Schedule B - Minimum Monitoring and Reporting Requirements In 1988, the Department developed a monitoring matrix for commonly monitored parameters. Proposed monitoring frequencies for all parameters are based on this matrix. The proposed monitoring frequencies for all parameters correspond to those of facilities of similar size and complexity in the state.
An introductory paragraph has been added to Schedule B identifying the requirement for laboratory quality assurance/quality control (QA/QC) and how analytical results are to be handled with respect to calculations and reporting if they do not meet QA/QC requirements.
In addition to the monitoring requirements in the previous permit, the new permit includes requirements for turbidity, background turbidity, and the weekly average of daily maximum temperature readings (calculation).
Discharge monitoring reports must be submitted to the Department monthly by the 15th day of the following month. The monitoring reports need to identify the principal operators designated by the Permittee to supervise the treatment and collection systems. The reports must also include records concerning application of biosolids and all applicable equipment breakdowns and bypassing.
Schedule C - Compliance Conditions The proposed permit does not contain any compliance conditions.
Schedule D - Special Conditions The proposed permit maintains an option for construction of a seepage bed, if necessary, to meet temperature limitations. Prior to construction, the location of the seepage bed, as well as detailed plans and specifications, must be approved in writing by the Department. The permittee must have the facilities supervised by personnel certified by the Department in the operation of treatment and/or collection systems. The other conditions in this schedule are standard verbiage.
General Conditions
The permittee must conform with all General Conditions including, but not limited to, conditions relating to operation and maintenance of pollution controls, monitoring and record keeping, and reporting requirements.
The General Conditions were revised in 2008. A summary of the changes is as follows: • There are additional citations to the federal Clean Water Act and CFR, including references to standards for sewage sludge use or disposal. • There is additional language regarding federal penalties. • Bypass language has been made consistent with the Code of Federal Regulations. • Overflow language has been modified. Formerly the language stated that overflows in response to the five or ten year event would not violate the permit. Now it states that overflows are prohibited. Meadows Utilities LLC Evaluation Report Page 9
DEQ will continue to exercise enforcement discretion with respect to overflows consistent with the provisions of the Bacteria Rule (OAR 340-041-0009). Reporting requirements regarding overflows have been made more explicit. Requirements regarding emergency response and public notification plans have been made more explicit. Language pertaining to duty to provide information has been made more explicit. Confidentiality of information is addressed.
Calculation of pH of a mixture of two flows. 10/14/2009 Based on the procedure in EPA's DESCON program (EPA, 1988. Technical Guidance on Supplementary Stream Design Conditions for Steady State Modeling. USEPA Office of Water, Washington D.C.)
RPAforpH INPUT ;':;>; V:^;->•'.: = Lower pH Upper pH .•' ' •"•'-.-.'.-..';/:.'.;;C. r-iV„'• 7. _v .. '. '. ' ' ' • '•'••''• ••^:''-'•"•" \':'' ''V/"Criteri a Criteria
1. DILUTION FACTOR AT MZ BOUNDARY - (Qe+Qr)/Qe 67 67
2. UPSTREAM/BACKGROUND CHARACTERISTICS Temperature (degC): 11.9 11.9
pH: f-Lr':y. y 6.5 8,0
Alkalinity (mgCaC03/L): :-:—-... .:y:25-:0' 25.0
3. EFFLUENT CHARACTERISTICS Temperature (degC): 16.5 16.5 pH: .6.0 9.0 Alkalinity (mg CaC03/L): yyv>;v;rv70;0.-: v; ;7p.a 4. APPLICABLE PH CRITERIA 6.5 8.5
: 0^jl^'f^^^;P^i:^---''-:y - '-'•'• '^V !;V-Vfn4,r:;^::;\:/V "..';. ...".:.. '... : v-~. v •:• '.'. ^~J-~':kK 1. IONIZATION CONSTANTS Upstream/Background pKa: 6.45 6.45 Effluent pKa: 6.41 6.41 2. IONIZATION FRACTIONS Upstream/Background Ionization Fraction: 0.53 0.97 Effluent Ionization Fraction: 0.28 1.00 3. TOTAL INORGANIC CARBON Upstream/Background Total Inorganic Carbon (mg CaC03/L) 47.09 25.70 Effluent Total Inorganic Carbon (mg CaC03/L): 249.13 70.18 4. CONDITIONS AT MIXING ZONE BOUNDARY Temperature (deg C): 12.01 12.01 Alkalinity (mg CaC03/L): 25.67 25.67 Total Inorganic Carbon (mg CaC03/L): 50.10 26.36 pKa: 6.45 6.45 pH at Mixing Zone Boundary: 6.5 8.0 Is there Reasonable Potential? No No
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