| Water Body Name: | Heavenly Creek, unknown tributary |
| Water Body ID: | CAR6341003020171227031332 |
| Water Body Type: | River & Stream |
DECISION ID |
103479 |
Region 6 |
Heavenly Creek, unknown tributary |
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| Pollutant: | Benthic Community Effects |
| 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: | Pollution |
| Regional Board Staff Conclusion: | Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects.
One line of evidence evaluating benthic-macroinvertebrate bioassessment data is available in the administrative record to assess this indicator. 2 of 4 benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold and indicate that the stream is 'very likely altered'. This exceedance frequency exceeds the allowable frequency as stipulated by section 3.9 of the Listing Policy. Bioassessment samples alone cannot support the addition of this pollutant/waterbody combination to the 303(d) list however. Water quality data pertaining to other water or sediment concentrations of pollutants are required to fully assess listing status. The Regional Board decision is to not list this waterbody at this time pending further water quality monitoring. It is likely that this waterbody segment is being degraded by regular operations at the Heavenly Mountain ski resort. The waterbody segment directly downstream of this waterbody, Heavenly Valley Creek (source to USFS boundary), will be listed during the 2018 cycle for benthic community effects as there is requisite benthic and water chemistry data to support the addition of the waterbody to the 303(d) list of impaired waters. The Regional Board has placed this waterbody segment on the bioassessment prioritization list for further investigation. Based on the readily available data and information, the weight of evidence indicates that there is insufficient information to justify placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List, although the available data indicates that impairment in this waterbody reach is probable. 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. 2 of 4 benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. Therefore, this water body is exceeding the water quality threshold for the protection of the COLD beneficial use. Without further water quality data to assess the conditions in this waterbody segment it is not possible to fully assess listing status and the Regional Board decides not to list this waterbody segment at this time pending further investigation. 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 Staff 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. |
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| LOE ID: | 96454 | ||||
| Pollutant: | Benthic-Macroinvertebrate Bioassessments | ||||
| LOE Subgroup: | Population/Community Degradation | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Cold Freshwater Habitat | ||||
| Number of Samples: | 4 | ||||
| Number of Exceedances: | 2 | ||||
| Data and Information Type: | Benthic macroinvertebrate surveys | ||||
| Data Used to Assess Water Quality: | There were four CSCI scores from this site. The scores were:
0.925598693 0.882328887 0.607069579 0.259077691 Two of the four scores were exceeding the water quality objective for the aquatic life beneficial use. It should be noted that the low scores were the older two scores. The more recent score meet the objective. |
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| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Heavenly Valley TMDL. | ||||
| SWAMP Data: | |||||
| Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended) | ||||
| Evaluation Guideline: | The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rhen, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. | ||||
| Guideline Reference: | The California Stream Condition Index (CSCI): A New Statewide Biological Scoring Tool for Assessing the Health of Freshwater Streams. | ||||
| Spatial Representation: | Samples were collected at station 634HVC-1 | ||||
| Temporal Representation: | Samples were collected on the following dates:
6/11/2015 7/20/2016 8/29/2011 7/28/2014 |
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| Environmental Conditions: | |||||
| QAPP Information: | QAPP for Heavenly Valley TMDL | ||||
| QAPP Information Reference(s): | Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program | ||||