| Water Body Name: | Trout Creek (below Hwy 50) |
| Water Body ID: | CAR6341003120020117091520 |
| Water Body Type: | River & Stream |
DECISION ID |
80021 |
Region 6 |
Trout Creek (below Hwy 50) |
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| Pollutant: | Indicator Bacteria |
| Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)(2016) |
| Revision Status | Revised |
| Sources: | Source Unknown |
| Expected TMDL Completion Date: | 2031 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Staff Conclusion: | Regional Board Conclusion:
This pollutant was considered for removal on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged and is as follows: This pollutant is being considered for removal from the section 303(d) list under section 4.2 of the Listing Policy. Under this section 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. Three log mean datapoints exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Three of 19 log mean datapoints exceeded the water quality objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 4.2. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. The listing was previously for "Pathogens" the pollutant name has been changed to "Fecal Coliform" for clarity and consistency. For the 2018 cycle the pollutant name has been updated to 'Indicator Bacteria'. |
| Regional Board Staff Decision Recommendation: | This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same. |
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| LOE ID: | 4649 | ||||
| Pollutant: | Pathogens | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Not Specified | ||||
| Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006. | ||||
| Data Reference: | Placeholder reference pre-2006 303(d) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Unspecified | ||||
| Objective/Criterion Reference: | Placeholder reference pre-2006 303(d) | ||||
| Evaluation Guideline: | Unspecified | ||||
| Guideline Reference: | Placeholder reference pre-2006 303(d) | ||||
| Spatial Representation: | Unspecified | ||||
| Temporal Representation: | Unspecified | ||||
| Environmental Conditions: | Unspecified | ||||
| QAPP Information: | Unspecified | ||||
| QAPP Information Reference(s): | |||||
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| LOE ID: | 27160 | ||||
| Pollutant: | Fecal Coliform | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 19 | ||||
| Number of Exceedances: | 3 | ||||
| Data and Information Type: | Water column surveys (e.g. fecal coliform) | ||||
| Data Used to Assess Water Quality: | This assessment uses data collected and analyzed by Lahontan RWQCB staff in 2008. It focuses on violations of the 20/100 mL limit. Data were evaluated as 30-day log normalized means. There were 19 log mean datapoints, with three datapoints in violation of the objective. | ||||
| Data Reference: | 2009. Determination of Fecal Coliform Violations of Lahontan Basin Plan Water Quality Objectives: Data Reduction Procedure | ||||
| 2008 Non-Point Source (NPS) Fecal Coliform Data (colonies/100 mL) for Trout Creek | |||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states:
"Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock waste. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected a evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected." |
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| Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended) | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Data were collected at the confluence of Trout Creek with the Upper Truckee River near Lake Tahoe. | ||||
| Temporal Representation: | The data used were collected in between July and December 2008. | ||||
| Environmental Conditions: | Trout Creek joins the Upper Truckee River near the south shore of Lake Tahoe. Livestock grazing formerly occurred in the meadow near the confluence. | ||||
| QAPP Information: | The data were collected and analyzed using the Lahontan RWQCB's quality assurance protocols. | ||||
| QAPP Information Reference(s): | |||||
DECISION ID |
69978 |
Region 6 |
Trout Creek (below Hwy 50) |
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| Pollutant: | Iron |
| Final Listing Decision: | List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2016) |
| Revision Status | Original |
| Sources: | Source Unknown |
| Expected TMDL Completion Date: | 2019 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Staff Conclusion: | Regional Board Conclusion:
This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed. |
| Regional Board Staff Decision Recommendation: | This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same. |
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| LOE ID: | 4647 | ||||
| Pollutant: | Iron | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Municipal & Domestic Supply | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Not Specified | ||||
| Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006. | ||||
| Data Reference: | Placeholder reference pre-2006 303(d) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Unspecified | ||||
| Objective/Criterion Reference: | Placeholder reference pre-2006 303(d) | ||||
| Evaluation Guideline: | Unspecified | ||||
| Guideline Reference: | Placeholder reference pre-2006 303(d) | ||||
| Spatial Representation: | Unspecified | ||||
| Temporal Representation: | Unspecified | ||||
| Environmental Conditions: | Unspecified | ||||
| QAPP Information: | Unspecified | ||||
| QAPP Information Reference(s): | |||||
DECISION ID |
80293 |
Region 6 |
Trout Creek (below Hwy 50) |
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| Pollutant: | Nitrogen |
| Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL)(2016) |
| Revision Status | Original |
| Sources: | Source Unknown |
| TMDL Name: | Lake Tahoe Nutrients/Sediment |
| TMDL Project Code: | 198 |
| Date TMDL Approved by USEPA: | 08/16/2011 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. 303(d) listing decisions made prior to 2006 were not held in an assessment database.
Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Board will update this decision when new data and information become available and are assessed. No new information was reviewed for this current assessment cycle; however, the previous conclusion has changed since the Lake Tahoe TMDL, which partly addresses the nitrogen impairment within this segment of Trout Creek, was adopted after the 2010 Integrated Report. Trout Creek (below Hwy 50) is a tributary to Lake Tahoe. The Lake Tahoe TMDL includes an implementation plan that identifies actions that resource management agencies, Lake Tahoe municipalities (El Dorado and Placer Counties, City of South Lake Tahoe) and California Department of Transportation (CalTrans) must take to reduce inputs of nutrients (nitrogen and phosphorus) and fine sediment. On the ground efforts required by the Lake Tahoe TMDL that focus on (1) stabilizing disturbed areas within the forested uplands, (2) restoring eroding stream channels, and (3) managing and treating urban uplands (e.g. street sweeping, installing and maintaining infiltration and stormwater treatment facilities) will also achieve pollutant load reductions in waters tributary to Lake Tahoe. The largest source of nitrogen in the Lake Tahoe (and Trout Creek) watershed is transportation-related emissions that lead to atmospheric nitrogen deposition. The Lake Tahoe TMDL also includes implementation measures to reduce atmospheric nitrogen sources. The Tahoe Regional Planning Agency leads efforts to improve transportation infrastructure and reduce overall vehicle miles traveled in the Lake Tahoe region to reduce emissions that lead to atmospheric nutrient loading. Public transit and vehicle fleet turnover are expected to further reduce nutrient-laden emissions in the Tahoe basin that will reduce nitrogen loading in the Trout Creek watershed. Furthermore, Federal, State, and larger local restoration agencies have well defined multi objective watershed restoration programs. These programs include maintenance activities (e.g., fuels reduction projects and restoring small disturbed sites) that are underway, or planned and expected, within the forested uplands of this watershed. Implementation of these measures will reduce or avoid increases in fine sediment and nutrient loads to Lake Tahoe and its tributaries including Trout Creek below Hwy 50. Finally, recent restoration efforts directly upstream of this segment of Trout Creek completed by the City of South Lake Tahoe have restored geomorphic and hydrologic function and treatment of bankfull flows to help reduce nitrogen loading to this segment of Trout Creek. Pollutant load reductions within Trout Creek (below Hwy 50) will be tracked through implementation of detailed performance and compliance measures and assessment and reporting protocols included in the Lake Tahoe TMDL. The TMDL Management System project is establishing activity-based tracking and reporting requirements to assess activities that are expected to reduce pollutant loading from non-urban sources. The Lahontan Water Board and the Nevada Division of Environmental Protection will implement a Lake Tahoe TMDL Management System for managing, tracking, integrating and evaluating new information generated from TMDL implementation actions, effectiveness monitoring, research efforts, and other factors such as climate change and wildfires. The Management System is based on an adaptive management framework to (1) link load reduction effectiveness with project implementation monitoring to improve project design and to assess if actual environmental improvement is occurring as expected; (2) establish guidance and operation protocols for how new information will be incorporated into project designs and TMDL program implementation; (3) establish prioritized TMDL research needs to fill data gaps and reduce uncertainties, and (4) implement a process for updating and reporting pollutant load reduction estimates and tracking projects within the TMDL implementation timeline. The Lake Tahoe TMDL requires implementation, effectiveness, and status and trends monitoring. Tributary stream status and trends monitoring will track long-term changes in water quality conditions relative to established water quality standards or goals, and project-specific monitoring will be used to assess the efficacy of various implementation measures. Long-term water quality trends and pollutant load reduction tracking in Trout Creek (below Hwy 50) will be captured through the ongoing efforts of the Lake Tahoe Interagency Monitoring Program (LTIMP) whose primary objective is to monitor discharge, nutrient load, and sediment loads from representative streams that flow into Lake Tahoe. Nitrogen and phosphorus loading calculations are performed using the LTIMP flow and nutrient concentration database. LTIMP has monitored Trout Creek (below Hwy 50) and other tributaries to Lake Tahoe since 1988; this data is stored on the USGS website at http://wdr.water.usgs.gov/. |
| Regional Board Staff Decision Recommendation: | This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same. |
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| LOE ID: | 4648 | ||||
| Pollutant: | Nitrogen | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Cold Freshwater Habitat | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Not Specified | ||||
| Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006. | ||||
| Data Reference: | Placeholder reference pre-2006 303(d) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Unspecified | ||||
| Objective/Criterion Reference: | Placeholder reference pre-2006 303(d) | ||||
| Evaluation Guideline: | Unspecified | ||||
| Guideline Reference: | Placeholder reference pre-2006 303(d) | ||||
| Spatial Representation: | Unspecified | ||||
| Temporal Representation: | Unspecified | ||||
| Environmental Conditions: | Unspecified | ||||
| QAPP Information: | Unspecified | ||||
| QAPP Information Reference(s): | |||||
DECISION ID |
79669 |
Region 6 |
Trout Creek (below Hwy 50) |
||
| Pollutant: | Phosphorus |
| Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL)(2016) |
| Revision Status | Original |
| Sources: | Source Unknown |
| TMDL Name: | Lake Tahoe Nutrients/Sediment |
| TMDL Project Code: | 198 |
| Date TMDL Approved by USEPA: | 08/16/2011 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Board will update this decision when new data and information become available and are assessed.
No new information was reviewed for this current assessment cycle; however, the previous conclusion has changed since the Lake Tahoe TMDL, which partly addresses the phosphorus impairment within this segment of Trout Creek, was adopted after the 2010 Integrated Report. Trout Creek below Hwy 50 is a tributary to Lake Tahoe. The primary source of phosphorus in the Lake Tahoe (and Trout Creek) watershed is urban storm water runoff and phosphorus associated with eroding sediment on disturbed undeveloped lands. The Tahoe TMDL implementation plan identifies actions that resource management agencies, Lake Tahoe municipalities (El Dorado and Placer Counties, and the City of South Lake Tahoe) and California Department of Transportation (CalTrans) must take to reduce inputs of nutrients (nitrogen and phosphorus) and fine sediment in urban runoff discharges. On the ground efforts required by the Lake Tahoe TMDL that focus on (1) stabilizing disturbed areas within the forested uplands, (2) restoring eroding stream channels, and (3) managing and treating urban uplands (e.g. street sweeping, installing and maintaining infiltration and stormwater treatment facilities) will also achieve pollutant load reductions in waters tributary to Lake Tahoe. Municipal Stormwater NPDES permits require the Lake Tahoe municipalities and CalTrans to develop and implement comprehensive pollutant load reduction programs (PLRPs) to meet specified pollutant load reduction requirements. Expected implementation measures include a variety of alternative treatment options, roadway operation practices, and local ordinances to reduce average annual pollutant loads. These Lake Tahoe TMDL implementation efforts will also reduce inputs of phosphorus to this impaired segment of Trout Creek below Hwy 50. Maintenance activities and restoring small disturbed sites that are underway, or planned and expected, within the forested uplands of this watershed will also reduce or avoid increases in fine sediment and nutrient loads. Additionally, the Lake Tahoe TMDL also requires implementation of measures to control stationary sources of dust which help reduce pollutant loads of fine sediments. Implementation of these measures helps address the phosphorus loading that impairs Trout Creek below Hwy 50 that is associated with these fine sediments from dust sources. Federal, State, and larger local restoration agencies have well defined multi objective restoration programs with established funding and developed restoration plans. Recent restoration efforts directly upstream of this segment of Trout Creek that were completed by the City of South Lake Tahoe restored geomorphic and hydrologic function and treatment of bankfull flows to help reduce phosphorus loading to this segment of Trout Creek. Pollutant load reductions within Trout Creek (below Hwy 50) will be tracked through implementation of detailed performance and compliance measures and assessment and reporting protocols included in the Lake Tahoe TMDL. The TMDL Management System project is establishing activity-based tracking and reporting requirements to assess activities that are expected to reduce pollutant loading from non-urban sources. The Lahontan Water Board and the Nevada Division of Environmental Protection will implement a Lake Tahoe TMDL Management System for managing, tracking, integrating and evaluating new information generated from TMDL implementation actions, effectiveness monitoring, research efforts, and other factors such as climate change and wildfires. The Management System is based on an adaptive management framework to (1) link load reduction effectiveness with project implementation monitoring to improve project design and to assess if actual environmental improvement is occurring as expected; (2) establish guidance and operation protocols for how new information will be incorporated into project designs and TMDL program implementation; (3) establish prioritized TMDL research needs to fill data gaps and reduce uncertainties, and (4) implement a process for updating and reporting pollutant load reduction estimates and tracking projects within the TMDL implementation timeline. The Lake Tahoe TMDL requires implementation, effectiveness, and status and trends monitoring. Tributary stream status and trends monitoring will track long-term changes in water quality conditions relative to established water quality standards or goals, and project-specific monitoring will be used to assess the efficacy of various implementation measures. Long-term water quality trends and pollutant load reduction tracking in Trout Creek (below Hwy 50) will be captured through the ongoing efforts of the Lake Tahoe Interagency Monitoring Program (LTIMP) whose primary objective is to monitor discharge, nutrient load, and sediment loads from representative streams that flow into Lake Tahoe. Nitrogen and phosphorus loading calculations are performed using the LTIMP flow and nutrient concentration database. LTIMP has monitored Trout Creek (below Hwy 50) and other tributaries to Lake Tahoe since 1988; this data is stored on the USGS website at http://wdr.water.usgs.gov/. |
| Regional Board Staff Decision Recommendation: | This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same. |
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| LOE ID: | 4650 | ||||
| Pollutant: | Phosphorus | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Cold Freshwater Habitat | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Not Specified | ||||
| Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006. | ||||
| Data Reference: | Placeholder reference pre-2006 303(d) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Unspecified | ||||
| Objective/Criterion Reference: | Placeholder reference pre-2006 303(d) | ||||
| Evaluation Guideline: | Unspecified | ||||
| Guideline Reference: | Placeholder reference pre-2006 303(d) | ||||
| Spatial Representation: | Unspecified | ||||
| Temporal Representation: | Unspecified | ||||
| Environmental Conditions: | Unspecified | ||||
| QAPP Information: | Unspecified | ||||
| QAPP Information Reference(s): | |||||