| Water Body Name: | Trinidad HU, Big Lagoon HA, McConnahas Mill Creek |
| Water Body ID: | CAR1081000020180430045568 |
| Water Body Type: | River & Stream |
DECISION ID |
163577 |
Region 1 |
Trinidad HU, Big Lagoon HA, McConnahas Mill Creek |
||
| Pollutant: | Indicator Bacteria |
| Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) was adopted on August 7, 2018, and contains bacteria water quality objectives applicable to the REC-1 beneficial use. This has resulted in a change from assessing fecal coliform to assessing E. coli in fresh water and Enterococcus in saline water. Fecal coliform lines of evidence used in previous indicator bacteria decisions in the North Coast Region have been retired. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Lacking constant inputs, indicator bacteria do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of E. coli in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Historic lines of evidence for data collected prior to October 21, 2012 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. This waterbody has one LOE (327756), which is data from a sheet flow sample and not a receiving water, so the data was not used in the assessment. Beneficial use support will be reassessed in a future cycle, if more data are available. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded. |
|
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| LOE ID: | 327756 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | STV | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 8 | ||||
| Number of Exceedances: | 2 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Cher-Ae Heights Indian Community of the Trinidad Rancheria, California (Tribal) data for Trinidad HU, Big Lagoon HA, McConnahas Mill Creek to determine beneficial use support and the results are as follows: 2 of the 8 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | WQX from the NWQMP for the 2026 Integrated Report in Region 1 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site(s), station(s): TRINIDADRANCHERIAEPA-TH-2 (Trinidad Housing-2). | ||||
| Temporal Representation: | The samples were collected between the days of 2016-12-14 and 2021-10-27 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Cher-Ae Heights Indian Community of the Trinidad Rancheria QA | ||||
| QAPP Information Reference(s): | Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference | ||||
DECISION ID |
161395 |
Region 1 |
Trinidad HU, Big Lagoon HA, McConnahas Mill Creek |
||
| Pollutant: | Nitrogen, Nitrate |
| Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded. |
|
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| LOE ID: | 328732 | ||||
| Pollutant: | Nitrate as Nitrate (NO3) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Total | ||||
| Beneficial Use: | Municipal & Domestic Supply | ||||
| Number of Samples: | 11 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Cher-Ae Heights Indian Community of the Trinidad Rancheria, California (Tribal) data for Trinidad HU, Big Lagoon HA, McConnahas Mill Creek to determine beneficial use support and results are as follows: 0 of 11 samples exceeded the water quality threshold for Nitrate as NO3. | ||||
| Data Reference: | WQX from the NWQMP for the 2026 Integrated Report in Region 1 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The California Maximum Contaminant Level for nitrate (as NO3) incorporated by reference in the Water Quality Control Plan, North Coast Basin is 45.0 mg/L (Water Quality Control Plan, North Coast Basin). | ||||
| Objective/Criterion Reference: | Water Quality Control Plan (Basin Plan) for the North Coast Region | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site: TRINIDADRANCHERIAEPA-TH-2 (Trinidad Housing-2). | ||||
| Temporal Representation: | The samples were collected between the dates of 2012-12-18 and 2021-10-27 | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Cher-Ae Heights Indian Community of the Trinidad Rancheria QA | ||||
| QAPP Information Reference(s): | Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference | ||||
DECISION ID |
158669 |
Region 1 |
Trinidad HU, Big Lagoon HA, McConnahas Mill Creek |
||
| Pollutant: | Oxygen, Dissolved |
| Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. For the COLD FRESHWATER HABITAT beneficial use, there is one line of evidence and 0 of 65 samples exceed the objective, which does not exceed the allowable frequency in Table 3.2 of the Listing Policy. For the FISH SPAWNING beneficial use, there is one line of evidence and 5 of the 65 samples exceed the objective, which does not exceed the allowable frequency in Table 3.2 of the Listing Policy. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. For the COLD beneficial use, 0 of 65 samples, and for the SPWN beneficial use, 5 of 65 samples, exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | |
|
|||||
| LOE ID: | 328882 | ||||
| Pollutant: | Oxygen, Dissolved | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Fish Spawning | ||||
| Number of Samples: | 65 | ||||
| Number of Exceedances: | 5 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Cher-Ae Heights Indian Community of the Trinidad Rancheria, California (Tribal) data for Trinidad HU, Big Lagoon HA, McConnahas Mill Creek to determine beneficial use support and results are as follows: 5 of 65 samples exceeded the water quality threshold for Oxygen, Dissolved. | ||||
| Data Reference: | WQX from the NWQMP for the 2026 Integrated Report in Region 1 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states: Dissolved oxygen concentrations shall conform to those limits listed in Section 3.3.5. Section 3.3.5 lists dissolved oxygen concentration limits for SPAWN beneficial use waters to be a daily minimum of 9.0 mg/L and a 7-day moving average of 11.0 mg/L. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan (Basin Plan) for the North Coast Region | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site: TRINIDADRANCHERIAEPA-TH-2 (Trinidad Housing-2). | ||||
| Temporal Representation: | The samples were collected between the dates of 2017-05-12 and 2022-10-20 | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Cher-Ae Heights Indian Community of the Trinidad Rancheria QA | ||||
| QAPP Information Reference(s): | Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference | ||||
|
|||||
| LOE ID: | 328857 | ||||
| Pollutant: | Oxygen, Dissolved | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Cold Freshwater Habitat | ||||
| Number of Samples: | 65 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Cher-Ae Heights Indian Community of the Trinidad Rancheria, California (Tribal) data for Trinidad HU, Big Lagoon HA, McConnahas Mill Creek to determine beneficial use support and results are as follows: 0 of 65 samples exceeded the water quality threshold for Oxygen, Dissolved. | ||||
| Data Reference: | WQX from the NWQMP for the 2026 Integrated Report in Region 1 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states: Dissolved oxygen concentrations shall conform to those limits listed in Section 3.3.5. Section 3.3.5 lists dissolved oxygen concentration limits for COLD beneficial use waters to be a daily minimum of 6.0 mg/L and a 7-day moving average of 8.0 mg/L. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan (Basin Plan) for the North Coast Region | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site: TRINIDADRANCHERIAEPA-TH-2 (Trinidad Housing-2). | ||||
| Temporal Representation: | The samples were collected between the dates of 2017-05-12 and 2022-10-20 | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Cher-Ae Heights Indian Community of the Trinidad Rancheria QA | ||||
| QAPP Information Reference(s): | Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference | ||||
DECISION ID |
163078 |
Region 1 |
Trinidad HU, Big Lagoon HA, McConnahas Mill Creek |
||
| Pollutant: | Specific Conductivity |
| Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for conventional or other pollutants (Table 3.2 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | |
|
|||||
| LOE ID: | 329137 | ||||
| Pollutant: | Specific Conductivity | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Municipal & Domestic Supply | ||||
| Number of Samples: | 65 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Cher-Ae Heights Indian Community of the Trinidad Rancheria, California (Tribal) data for Trinidad HU, Big Lagoon HA, McConnahas Mill Creek to determine beneficial use support and results are as follows: 0 of 65 samples exceeded the water quality threshold for SpecificConductivity. | ||||
| Data Reference: | WQX from the NWQMP for the 2026 Integrated Report in Region 1 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15, Division 4, Article 4, Section 64435 (Tables 2 and 3), and Section 64444.5 (Table 5), and listed in Table 3-2 of this Plan (Water Quality Control Plan, North Coast Basin). | ||||
| Objective/Criterion Reference: | Water Quality Control Plan (Basin Plan) for the North Coast Region | ||||
| Evaluation Guideline: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Basin Plan's 'Chemical Constituents' objective. The California Secondary MCL for specific conductivity is 900 uS/cm. | ||||
| Guideline Reference: | California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring | ||||
| Spatial Representation: | The samples were collected at 1 monitoring site: TRINIDADRANCHERIAEPA-TH-2 (Trinidad Housing-2). | ||||
| Temporal Representation: | The samples were collected between the dates of 2017-05-12 and 2022-10-20 | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Cher-Ae Heights Indian Community of the Trinidad Rancheria QA | ||||
| QAPP Information Reference(s): | Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference | ||||
DECISION ID |
158671 |
Region 1 |
Trinidad HU, Big Lagoon HA, McConnahas Mill Creek |
||
| Pollutant: | Temperature, water |
| Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of 125 samples exceed the COLD beneficial use objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of 125 samples exceed the COLD beneficial use objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | |
|
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| LOE ID: | 329271 | ||||
| Pollutant: | Temperature, water | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Cold Freshwater Habitat | ||||
| Number of Samples: | 125 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Cher-Ae Heights Indian Community of the Trinidad Rancheria, California (Tribal) data for Trinidad HU, Big Lagoon HA, McConnahas Mill Creek to determine beneficial use support and results are as follows: 0 of 125 samples exceeded the water quality threshold for Temperature. | ||||
| Data Reference: | WQX from the NWQMP for the 2026 Integrated Report in Region 1 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. At no time or place shall the temperature of any COLD water be increased more than 5 degrees Fahrenheit (F) above natural receiving water temperature (Basin Plan, North Coast Region). | ||||
| Objective/Criterion Reference: | Water Quality Control Plan (Basin Plan) for the North Coast Region | ||||
| Evaluation Guideline: | According to Carter (2008) the lethal temperature evaluation guideline for salmonid spawning, egg incubation & fry emergence is 20C. | ||||
| Guideline Reference: | Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region | ||||
| Spatial Representation: | The samples were collected at 1 monitoring site: TRINIDADRANCHERIAEPA-TH-2 (Trinidad Housing-2). | ||||
| Temporal Representation: | The samples were collected between the dates of 2010-12-20 and 2022-10-20 | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Cher-Ae Heights Indian Community of the Trinidad Rancheria QA | ||||
| QAPP Information Reference(s): | Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference | ||||
DECISION ID |
158672 |
Region 1 |
Trinidad HU, Big Lagoon HA, McConnahas Mill Creek |
||
| Pollutant: | Turbidity |
| Final Listing Decision: | List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Sources: | A Source Unknown |
| TMDL Priority: | Low |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One lines of evidence are available in the administrative record to assess this pollutant. Eighteen of 33 samples exceed the guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eighteen of 33 samples exceed the guideline and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. This listing applies to the entire waterbody. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | |
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| LOE ID: | 329354 | ||||
| Pollutant: | Turbidity | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Municipal & Domestic Supply | ||||
| Number of Samples: | 33 | ||||
| Number of Exceedances: | 18 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Cher-Ae Heights Indian Community of the Trinidad Rancheria, California (Tribal) data for Trinidad HU, Big Lagoon HA, McConnahas Mill Creek to determine beneficial use support and results are as follows: 18 of 33 samples exceeded the water quality threshold for Turbidity. | ||||
| Data Reference: | WQX from the NWQMP for the 2026 Integrated Report in Region 1 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15, Division 4, Article 4, Section 64435 (Tables 2 and 3), and Section 64444.5 (Table 5), and listed in Table 3-2 of this Plan (Water Quality Control Plan, North Coast Basin). | ||||
| Objective/Criterion Reference: | Water Quality Control Plan (Basin Plan) for the North Coast Region | ||||
| Evaluation Guideline: | California Maximum Contaminant Levels (MCLs) apply to ambient surface waters under the Basin Plan's 'Chemical Constituents' objective. The Secondary MCL for turbidity is 5 NTU. Calculation of a numeric objective for other beneficial uses requires comparison with upstream or other background data which may not be available as part of the data used for water quality assessment. | ||||
| Guideline Reference: | California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring | ||||
| Spatial Representation: | The samples were collected at 1 monitoring site: TRINIDADRANCHERIAEPA-TH-2 (Trinidad Housing-2). | ||||
| Temporal Representation: | The samples were collected between the dates of 2017-05-12 and 2022-10-20 | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Cher-Ae Heights Indian Community of the Trinidad Rancheria QA | ||||
| QAPP Information Reference(s): | Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference | ||||
DECISION ID |
158670 |
Region 1 |
Trinidad HU, Big Lagoon HA, McConnahas Mill Creek |
||
| Pollutant: | pH |
| Final Listing Decision: | List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Sources: | A Source Unknown |
| TMDL Priority: | Low |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Twenty-seven of the 65 samples exceed the Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty-seven of 65 samples exceed the Objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | |
|
|||||
| LOE ID: | 328911 | ||||
| Pollutant: | pH | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Cold Freshwater Habitat | ||||
| Number of Samples: | 65 | ||||
| Number of Exceedances: | 27 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Cher-Ae Heights Indian Community of the Trinidad Rancheria, California (Tribal) data for Trinidad HU, Big Lagoon HA, McConnahas Mill Creek to determine beneficial use support and results are as follows: 27 of 65 samples exceeded the water quality threshold for pH. | ||||
| Data Reference: | WQX from the NWQMP for the 2026 Integrated Report in Region 1 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 6.5 or raised above 8.5. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan (Basin Plan) for the North Coast Region | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 1 monitoring site: TRINIDADRANCHERIAEPA-TH-2 (Trinidad Housing-2). | ||||
| Temporal Representation: | The samples were collected between the dates of 2017-05-12 and 2022-10-20 | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Cher-Ae Heights Indian Community of the Trinidad Rancheria QA | ||||
| QAPP Information Reference(s): | Data collected by a California Tribe QAPP Approved by U.S. EPA QAPP Reference | ||||