Final California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: Lower Silver Creek subwatershed (Santa Clara County, tributary to Coyote Creek)
Water Body ID: CAR2053008020080624170225
Water Body Type: River & Stream
 
DECISION ID
99820
Region 2     
Lower Silver Creek subwatershed (Santa Clara County, tributary to Coyote Creek)
 
Pollutant: Trash
Final Listing Decision: Do Not Delist from 303(d) list (being addressed with action other than TMDL)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (being addressed with action other than TMDL)(2016)
Revision Status Original
Sources: A Source Unknown
Expected Attainment Date: 2029
Implementation Action Other than TMDL: This trash listing will be addressed by implementing the trash control provisions of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California through the NPDES MS4 permit applicable to this waterbody.
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.11 of the Listing Policy. Under section 3.11, listing may be proposed based on the situation-specific weight of evidence. One line of evidence is available in the administrative record to assess this pollutant. The line of evidence consists of data from field visits/trash surveys conducted according to the Urban Rapid Trash Assessment (URTA) methodology developed by the Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP). Based on the readily available trash assessment data for this waterbody, the weight of evidence indicates that there is sufficient justification available in favor of placing this water segment-pollutant combination to the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. Data have been evaluated that supports this decision. 2. The Urban Rapid Trash Assessment methodology results showed that this waterbody had transportable, Persistent, Buoyant Litter parameter scores in the marginal urban and poor category (indicating threat to Wildlife Habitat beneficial uses) at two different locations on the only date monitored. 3. This waterbody is considered impaired by trash because there were exceedances of the evaluation guideline (poor condition category for the trash assessment metric) in more than one location or on more than one date. 4. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 5. The data used satisfy the data quantity requirements of section 6.1 of the Policy.
6. This trash listing will be addressed by implementing the trash control provisions of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California through the NPDES MS4 permit applicable to this waterbody.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 99820, Trash
Region 2     
Lower Silver Creek subwatershed (Santa Clara County, tributary to Coyote Creek)
 
LOE ID: 5539
 
Pollutant: Trash
LOE Subgroup: Pollutant-Nuisance
Matrix: Not Specified
Fraction: None
 
Beneficial Use: Wildlife Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: Occurrence of conditions judged to cause impairment
Data Used to Assess Water Quality: Data results were obtained through application of the Urban Rapid Trash Assessment (URTA) methodology, developed by the Santa Clara Valley Urban Runoff Pollution Prevention Program. The URTA is a modification of the Rapid Trash Assessment (RTA) developed by the Surface Water Ambient Monitoring Program (SWAMP). The URTA method documents the total number and characteristics of pieces of trash per one hundred feet of stream or shoreline. The trash assessment protocol involves picking up and tallying all of the trash items found within the defined boundaries of a site. The tally results for level of trash (relating to REC2) and transportable, persistent, buoyant litter (relating to WILD) assessment parameters were considered for the listing determination. These results are available for field visits/trash surveys conducted in March 2005, according to the Urban Rapid Trash Assessment (URTA) methodology. This waterbody had transportable, Persistent, Buoyant Litter parameter scores in the marginal urban and poor category (indicating threat to Wildlife Habitat beneficial uses) at two different locations on the only date monitored.
Data Reference: Memo: Development of Urban Rapid Trash Assessment Protocol. March 13, 2006
  Spreadsheet of Urban Rapid Trash Assessment (URTA) data collected by the Santa Clara Valley Urban Runoff Pollution Prevention Program, 2004-2007
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan prohibits discharge of Rubbish, refuse, bark, sawdust, or other solid wastes into surface waters or at any place where they would contact or where they would be eventually transported to surface waters, including flood plain areas.

The Basin Plan has a narrative objective for floating material, Waters shall not contain floating material, including solids, liquids, foams, and scum, in concentrations that cause nuisance or adversely affect beneficial uses.

The Basin Plan has a narrative objective for settleable material, Waters shall not contain substances in concentrations that result in the deposition of material that cause nuisance or adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
 
Evaluation Guideline: If the URTA Parameter 3 (Transportable, Persistent, Buoyant Litter) is in the marginal urban or poor condition category (scores 0-10), then WILD is not supported. The URTA defines marginal urban or poor condition for this parameter as follows. this level of trash is a medium prevalence (76-200 pieces) or large amount (>200 pieces) of transportable, persistent, buoyant litter such as: hard or soft plastics, styrofoam, balloons, cigarette butts. These types of items are all detrimental to aquatic life.
Guideline Reference: Memo: Development of Urban Rapid Trash Assessment Protocol. March 13, 2006
 
Spatial Representation: URTA data were collected for this waterbody in three locations in March 2005.
Temporal Representation: URTA data were collected for this waterbody on only one date in March 2005.
Environmental Conditions:
QAPP Information: Data were collected by trained staff in accordance with URTA methodology developed by SCVURPPP and are deemed reliable and of sufficient quality on which to base listing determinations.
QAPP Information Reference(s):