| Water Body Name: | Trinidad HU, Big Lagoon HA, Luffenholtz Creek |
| Water Body ID: | CAR1081000020230405035390 |
| Water Body Type: | River & Stream |
DECISION ID |
163038 |
Region 1 |
Trinidad HU, Big Lagoon HA, Luffenholtz Creek |
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| 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 REC-1 beneficial use indicator bacteria decisions in the North Coast Region are not included in the 2026 Integrated Report assessment. the pollutant will again be considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. 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. The sampling station is on the Luffenholtz Beach. E. coli data are assessed for freshwater waterbodies and the samples were collected from Luffenholtz Beach, which is saline marine. Therefore, the LOEs were not assessed for this waterbody. 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 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: | 321846 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | STV | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 43 | ||||
| Number of Exceedances: | 8 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed BeachWatch-Humboldt County data for Trinidad HU, Big Lagoon HA, Luffenholtz Creek to determine beneficial use support and the results are as follows: 8 of the 43 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: | WQ from the BeachWatch 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): Luffenholtz Creek (Luffenholtz Creek-Luffenholtz Beach, Humboldt). | ||||
| Temporal Representation: | The samples were collected between the days of 2015-07-28 and 2022-10-17 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | QAPP for BeachWatch | ||||
| QAPP Information Reference(s): | QAPP Reference for Beach Watch Program | ||||
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| LOE ID: | 321847 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | GeoMean | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 154 | ||||
| Number of Exceedances: | 7 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed BeachWatch-Humboldt County data for Trinidad HU, Big Lagoon HA, Luffenholtz Creek to determine beneficial use support and the results are as follows: 7 of the 154 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly. | ||||
| Data Reference: | WQ from the BeachWatch 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 for waters where the salinity is equal to or less than 1 part per thousand 95 percent or more of the time applies a rolling six-week geometric mean of E. coli, not to exceed 100 cfu/100 mL (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): Luffenholtz Creek (Luffenholtz Creek-Luffenholtz Beach, Humboldt). | ||||
| Temporal Representation: | The samples were collected between the days of 2015-07-28 and 2022-10-17 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | QAPP for BeachWatch | ||||
| QAPP Information Reference(s): | QAPP Reference for Beach Watch Program | ||||