Draft California 2016 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name:	Stevens Creek
Water Body ID:	CAR2055002019990218134341
Water Body Type:	River & Stream


DECISION ID	33884	Region 2
Stevens Creek

Pollutant:	Toxicity
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2012)
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess pollutant. Two of six samples exceed the guideline. 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 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. Two of six samples exceed the guideline and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 33884, Toxicity	Region 2
Stevens Creek

LOE ID:

90507

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sample was collected to evaluate sediment toxicity. The sample exhibited significant toxicity. The toxicity test included survival and growth of Hyalella azteca. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 2 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted with the significant effect code SL. SL is defined as the result being significant compared to the negative control based on a statistical test, less than stated the alpha level, AND less than the evaluation threshold.

Guideline Reference:

Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064

Spatial Representation:

The sample was collected at station 205SUP101.

Temporal Representation:

The sample was collected in January 2007.

Environmental Conditions:

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 33884, Toxicity	Region 2
Stevens Creek

LOE ID:

28870

Pollutant:

Sediment Toxicity

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data used to evaluate sediment toxicity comprise one sediment sample collected by the SWAMP in 2002. This sample displayed statistically significant toxicity during the Hyalella azteca test. Hyalella azteca growth was only 71% of the control.

Data Reference:

Water Quality Monitoring and Bioassessment in Nine San Francisco Bay Region Watersheds: Walker Creek, Lagunitas Creek, San Leandro Creek, Wildcat Creek/San Pablo Creek, Suisun Creek, Arroyo Las Positas, Pescadero Creek/Butano Creek, San Gregorio Creek, and Stevens Creek/Permanente Creek. Oakland, CA: Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.

There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

Sediment toxicity was evaluated according to the SWAMP methodology. Sample toxicity was determined by comparing mean organism response in samples and in negative controls. Statistical evaluation (alpha = 0.05) and a default threshold of 80% of the control value were used to establish whether the sediment exhibited significant toxicity adversely impacting aquatic organisms.

Guideline Reference:

Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322?1329

Spatial Representation:

Data were collected at one sampling location at the lower part of Stevens Creek.

Temporal Representation:

A sample was collected in spring season 2002.

Environmental Conditions:

QAPP Information:

All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 33884, Toxicity	Region 2
Stevens Creek

LOE ID:

1806

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Toxicity testing of sediments

Data Used to Assess Water Quality:

Two out of six samples displayed significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria were met). The toxic Belleville/Barranca samples of April 2002 and January 2003 were 7 day tests for % survival of Pimephales promelas and Ceriodaphnia dubia, respectively. Please see also the QA qualifier below for the January 2003 toxic Belleville/Barranca sample (TSMP, 2002).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Basin Plan: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test.

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from two stations along Stevens Creek: Belleville/Barranca and La Avenida. Toxicity was detected in samples collected from the Belleville/Barranca site.

Temporal Representation:

Samples were collected at the two different stations on three dates, June 17, 2002, April 11, 2002, and January 23, 2003, for a total of six samples. Toxicity in the survival endpoint was detected in samples collected in April 2002 and January 2003.

Environmental Conditions:

Sub-Basin: Stevens Creek is in the Santa Clara Basin.

QAPP Information:

SWAMP QAPP. QA qualifier of Minor deviations in water quality parameters for the toxic January 2003 Barranca sample.

QAPP Information Reference(s):


DECISION ID	33996	Region 2
Stevens Creek

Pollutant:	Diazinon
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2012)
Revision Status	Revised
Sources:	Source Unknown
TMDL Name:	San Francisco Bay Urban Creeks Diazinon
TMDL Project Code:	9
Date TMDL Approved by USEPA:	05/21/2007
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and 4.1 of the Listing Policy. Under 4.1 of the Policy, a minimum of one line of evidence is needed to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. 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 CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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. A product ban for urban uses of diazinon in 1999 which has caused dramatic reduction in use. 4. Zero of one recent samples (since the ban) exceeded the evaluation guideline. 5. However, there are not a sufficient number of samples to de-list this waterbody according to Table 4.1 of the Listing Policy. 6. The Pesticides in Urban Creeks TMDL was approved by USEPA on 5/21/2007. 7. Pursuant to section 4.11 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 33996, Diazinon	Region 2
Stevens Creek

LOE ID:

93432

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Stevens Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

San Francisco Bay Basin Water Quality Control Plan 2007: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

There is no diazinon evaluation guideline specific to "sediment, interstitial water" (pore water). The following evaluation guideline was used to evaluate an exceedance in water quality standards: the freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).?

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83?92.

Spatial Representation:

Data for this line of evidence for Stevens Creek was collected at 1 monitoring site [ Stevens Ck @ HWY 82 station (205SUP101).]

Temporal Representation:

Data was collected on a single day 1/2/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 33996, Diazinon	Region 2
Stevens Creek

LOE ID:

1807

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

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 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QA Info Missing

QAPP Information Reference(s):


DECISION ID	34847	Region 2
Stevens 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:	List on 303(d) list (TMDL required list)(2012)
Revision Status	Revised
Sources:	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 three locations on three different dates in 2004, 2006 and 2007. 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.

Line of Evidence (LOE) for Decision ID 34847, Trash	Region 2
Stevens Creek

LOE ID:

5540

Pollutant:

Trash

LOE Subgroup:

Pollutant-Nuisance

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

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 2004 through 2007 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 three locations on three different dates in 2004, 2006 and 2007.

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 six locations in 2004 through 2007.

Temporal Representation:

URTA data were collected for this waterbody on seven dates in 2004 through 2007.

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):


DECISION ID	66841	Region 2
Stevens Creek

Pollutant:	Chlorpyrifos
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 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. Zero of zero samples exceed the guideline. Sediment toxicity data are not associated with this decision because they are not relevant to this decision because there is insufficient information based on sediment chemistry. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 zero samples exceed the guideline and this sample size is insufficient to determine beneficial use support, with the power and confidence of the Listing Policy. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. Sediment toxicity data are not associated with this decision because the sediment chemistry data are insufficient. 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. 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.

Line of Evidence (LOE) for Decision ID 66841, Chlorpyrifos	Region 2
Stevens Creek

LOE ID:

93431

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

One of one sample result was not used in the assessment because the sample was non-detect and the laboratory data method detection limit was above the guideline and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

There is no chlorpyrifos evaluation guideline specific to "sediment, interstitial water" (pore water). The following evaluation guideline was used to evaluate an exceedance in water quality standards: the freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).?

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Spatial Representation:

Data for this line of evidence for Stevens Creek was collected at 1 monitoring site [ Stevens Ck @ HWY 82 station (205SUP101).]

Temporal Representation:

Data was collected on a single day 1/2/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	43410	Region 2
Stevens Creek

Pollutant:	Ammonia (Unionized) \| Nitrogen, ammonia (Total Ammonia)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2012)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 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. None of the samples exceed the water quality 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 section 303(d) list in the Water Quality Limited Segments category. 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. None of nine samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 43410, Multiple Pollutants	Region 2
Stevens Creek

LOE ID:

28070

Pollutant:

Ammonia (Unionized) | Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Nine water samples were assessed for total ammonia and un-ionized ammonia. None of the samples exceeded the evaluation criteria.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The San Francisco Bay Regional Water Quality Board Basin Plan states: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.

The San Francisco Bay Regional Water Quality Board Basin Plan stated that the discharge of wastes shall not cause receiving water to contain concentrations of un-ionized ammonia in excess of 0.025mg/l annual median.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

For Total Ammonia: EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2006 edition of the drinking water standards and health advisories. This Advisory Level is defined as "the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure."

Guideline Reference:

2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013

Spatial Representation:

Nine samples from three monitoring locations (STE020, STE060, and STE100) were assessed.

Temporal Representation:

Samples were collected from three seasons, dry, spring and wet season of 2001-2002.

Environmental Conditions:

QAPP Information:

The QA was in compliance with SWAMP Quality Assurance Management Plan.

QAPP Information Reference(s):


DECISION ID	44307	Region 2
Stevens Creek

Pollutant:	Anthracene \| Benzo(a)anthracene \| Benzo(a)pyrene (3,4-Benzopyrene -7-d) \| Chlordane \| Chrysene (C1-C4) \| DDD (Dichlorodiphenyldichloroethane) \| DDE (Dichlorodiphenyldichloroethylene) \| DDT (Dichlorodiphenyltrichloroethane) \| Dieldrin \| Endrin \| Fluoranthene \| Fluorene \| Heptachlor epoxide \| Lindane/gamma Hexachlorocyclohexane (gamma-HCH) \| Naphthalene \| PAHs (Polycyclic Aromatic Hydrocarbons) \| PCBs (Polychlorinated biphenyls) \| Phenanthrene \| Pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2012)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	These pollutants are being considered for placement on the section 303(d) list under section 3.1 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 these pollutants. Zero samples exceed the water quality 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 section 303(d) list in the Water Quality Limited Segments category. 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 one sample exceed the water quality objective, but this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of two samples are needed for application of table 3.1. 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 44307, Multiple Pollutants	Region 2
Stevens Creek

LOE ID:

28512

Pollutant:

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Concentrations of anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg;
Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

One sediment sample was collected from the most downstream site of Stevens Creek at La Avenida.

Temporal Representation:

Sediment sample was collected in June of 2002.

Environmental Conditions:

QAPP Information:

All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).

QAPP Information Reference(s):


DECISION ID	44240	Region 2
Stevens Creek

Pollutant:	Arsenic \| Chromium (total) \| Copper \| Lead \| Nickel \| Silver \| Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2012)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 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. None of the samples exceed the water quality 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 section 303(d) list in the Water Quality Limited Segments category. 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. None of six samples exceeded the water quality objectives and this does not exceed the allowable frequency listed in Table 3.1 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 44240, Multiple Pollutants	Region 2
Stevens Creek

LOE ID:

27968

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The Stevens Creek watershed was monitored as part of SWAMP assessment. None of the six samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc.
Concentrations of total dissolved chromium were well below the objective for chromium VI.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Two monitoring locations (STE020 and STE060) were sampled in Stevens Creek.

Temporal Representation:

The samples were collected from three different seasons, wet, dry, and spring.

Environmental Conditions:

QAPP Information:

The Quality Control is is conducted in accordance with SWAMP's Quality Management Plan of 2002.

QAPP Information Reference(s):


DECISION ID	43403	Region 2
Stevens Creek

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2012)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 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. None of the samples exceed the water quality 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 section 303(d) list in the Water Quality Limited Segments category. 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. None of six samples exceeded the water quality guidelines and this does not exceed the allowable frequency listed in Table 3.1 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 43403, Cadmium	Region 2
Stevens Creek

LOE ID:

27992

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Six water samples were assessed. The concentration of cadmium in all six samples was less than the acute and chronic evaluation criteria.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan states that the objective is expressed by formulas where H=ln (hardness) as CaCO3 in mg/l: The four-day average objective for cadmium is e (exp 0.7852H - 3.490). This is 1.1 ug/l at a hardness of 100mg/l as CaCO3. The one hour objective is e (exp 1.128H - 3.828). This is 3.9ug/l at a hardness of 100mg/l as CaCO3.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from two monitoring locations: STE020 (the most downstream site) and STE060 (upstream portion of the creek).

Temporal Representation:

The samples were collected in three seasons, Spring, Wet and Dry seasons.

Environmental Conditions:

QAPP Information:

The QA/QC procedure was in compliance with Surface Water Ambient Monitoring Program's (SWAMP) Quality Assurance Management Plan (QAMP).

QAPP Information Reference(s):


DECISION ID	43411	Region 2
Stevens Creek

Pollutant:	Chlorpyrifos \| Dacthal \| Diazinon \| Disulfoton \| Endosulfan \| Lindane/gamma Hexachlorocyclohexane (gamma-HCH) \| Methyl Parathion \| PCBs (Polychlorinated biphenyls) \| Thiobencarb/Bolero
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2012)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 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. None of the samples exceed the water quality 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 section 303(d) list in the Water Quality Limited Segments category. 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. None of six samples exceeded the water quality guidelines and this does not exceed the allowable frequency listed in Table 3.1 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 43411, Multiple Pollutants	Region 2
Stevens Creek

LOE ID:

28991

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The Stevens Creek watershed was monitored as part of SWAMP assessment. None of the six samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.

Data Reference:

Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Diazinon water quality objective, 0.1 ug/L (acute)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).

Guideline Reference:

Spatial Representation:

Data were collected at two sampling locations: STE020 (La Avenida) and STE060 ("Belleville"/ Barranca) in Stevens Creek.

Temporal Representation:

Samples were collected at both locations during wet, spring, and dry seasons of the 2001 - 2002 sampling season.

Environmental Conditions:

QAPP Information:

All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	43557	Region 2
Stevens Creek

Pollutant:	Escherichia coli (E. coli)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2012)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 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. Two out of four samples exceed the water quality 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 section 303(d) list in the Water Quality Limited Segments category. 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. Two of four samples exceeded the number of Escherichia coli (E. Coli) counts, but this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of five samples are needed for application of table 3.2. 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 43557, Escherichia coli (E. coli)	Region 2
Stevens Creek

LOE ID:

29017

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Samples were collected as part of SWAMP sampling in the summer of 2002 at 7-day intervals and the geometric mean of the samples calculated over a five week interval. Samples were collected at four locations: STE020, STE070, STE080, and STE090. Monitoring occurred every 7 days for a total of 30 days. The geometric mean for STE020 was 796 MPN/100 mL, STE070 was 50 MPN/100 mL, STE080 was 92 MPN/100 mL, and STE090 was 182 MPN/100 mL. Two samples (STE020 and STE090) exceeded the 126 MPN/100ml criteria.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Uses of water for recreational activities involving body contact with water where ingestion of water is reasonably possible. These uses include, but are not limited to, swimming, wading, water-skiing, skin and scuba diving, surfing, whitewater activities, fishing, and uses of natural hot springs.

Water contact implies a risk of waterborne disease transmission and involves human health; accordingly, criteria required to protect this use are more stringent than those for more casual water-oriented recreation.
U.S. EPA water quality criteria for water contact recreation based on the frequency of use a particular area receives - 1986: the E. coli criterion is not to exceed 126 organisms/100 mL. The value is expressed as a 7-day geometric mean based on five or more samples per 30?day period; designated beach (max) 235 MPN/100 mL.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at STE020 (La Avenida), STE070 (Chestnut Picnic Area), STE080 (Above the Reservoir), and STE090 (Camp Cooley).

Temporal Representation:

Samples were collected weekly from 7/22/2002 through 8/19/2002.

Environmental Conditions:

QAPP Information:

All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	36182	Region 2
Stevens Creek

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2012)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	One line of evidence are available in the administrative record to assess this water body. Based on the readily available data for this water body, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. 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. Dissolved oxygen measurements at all 11 continuous deployments exceeded the applicable water quality objectives for waters designated as warm water habitat on one occasion, 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 36182, Oxygen, Dissolved	Region 2
Stevens Creek

LOE ID:

8678

Pollutant:

Low Dissolved Oxygen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data used to evaluate dissolved oxygen was collected by SWAMP in 2002-2003. In 1 out of 11 seasonal deployments, minimum dissolved oxygen levels fell below the objective of 5 mg/L. The deployment where this occurred was a lower watershed deployment during the dry season.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The numeric water quality objective for dissolved oxygen is 5.0 mg/L minimum for waters designated as warm freshwater habitat. The median dissolved oxygen concentration for any three consecutive months shall not be less than 80 percent of the dissolved oxygen content at saturation.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Dissolved oxygen was measured at four sites spanning lower to upper watershed locations on this creek.

Temporal Representation:

The SWAMP Program performed continuous monitoring of dissolved oxygen at 15 minute intervals for periods of 1-2 weeks in two dry seasons and one wet season in 2002-2003.

Environmental Conditions:

The Stevens Creek watershed is in the western Santa Clara Basin. The watershed of Stevens Creek is a 38 square mile drainage basin, with its headwaters high in the densely forested Santa Cruz Mountains. The upper portions of the watershed drains upland, mountainous or hilly landscapes where human development is largely absent. The lower portions of the streams flow through western Santa Clara Valley, a large flat alluvial valley draining into South San Francisco Bay. Land uses in the watershed include mining, urbanization, forests, and parks.

QAPP Information:

All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).

QAPP Information Reference(s):


DECISION ID	43556	Region 2
Stevens Creek

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2012)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 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. One of the samples exceeds the water quality 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 section 303(d) list in the Water Quality Limited Segments category. 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. One of eleven samples exceeded the water quality objectives 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 43556, pH	Region 2
Stevens Creek

LOE ID:

29006

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water quality assessment was conducted at the Stevens Creek watershed as part of SWAMP study in 2002-2003. Continuous field monitoring at 15 minute increments of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at one, three or four. Continuous monitoring sondes were deployed 11 times at 1, 3, or 4 monitoring locations during wet, spring and two dry seasons. The pH ranged from 7.13 to 8.65. The pH exceeded the threshold once (spring), but otherwise did not exceed or drop below the appropriate water quality threshold during any sampling event during the 2002-2003 season.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

pH was measured at one,three. or five sites located on the mainstream of Stevens Creek that are representative of the entire creek length.

Temporal Representation:

In 2002-2003 the SWAMP Program performed continuous monitoring of pH at 15 minute intervals for periods of 1-2 weeks in each of four seasons: winter (4 sites), spring (1 site), and two summer dry season (4, 3 sites).

Environmental Conditions:

QAPP Information:

All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	35334	Region 2
Stevens Creek

Pollutant:	Temperature, water
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)(2012)
Revision Status	Original
Sources:	Source Unknown
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for listing 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. A sufficient number of samples exceeds the water quality objective. Based on the readily available data for this water body, the weight of evidence indicates that there is sufficient justification available in favor of adding 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. The data concerning current conditions and supporting the listing decision were collected as part of the SWAMP and 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. Temperature measurements at 6 out of 11 continuous deployments exceeded the 17 ?C evaluation guideline used to interpret the water quality objective for waters designated as cold water habitat 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

Line of Evidence (LOE) for Decision ID 35334, Temperature, water	Region 2
Stevens Creek

LOE ID:

8543

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Comprehensive water quality assessment was conducted at the Stevens Creek watershed as part of SWAMP assessment. Continuous field monitoring at 15 minute increments of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at five locations throughout the watershed.

The measured temperatures ranged from 9.3?C to 25.5 ?C and varied with season and location. The 17 ?C criterion for steelhead was exceeded in 6 out of 11 deployments. Five exceedances were recorded in the dry season and 1 was measured in the wet season.

High water temperature exceeding 24 ?C, that is a maximum short exposure temperature for survival of salmonids (EPA 1977) was also measured at one monitoring location at lower reach of the Creek during summer dry season. At this monitoring site the leathal temperature for salmonids (< 24?C) persisted for 4.25 hours.

Data Reference:

Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Temperature objectives for enclosed bays and estuaries are specified in the Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays of California including any revisions to the plan. In addition, the following temperature objectives apply to surface waters: The 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.
The temperature of any cold or warm freshwater habitat shall not be increased by more than 5?F (2.8?C) above natural receiving water temperature.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)

Evaluation Guideline:

Sullivan et al. (2000) reviewed a wide range of studies incorporating information from laboratory-based research, field observations, and risk assessment approaches and developed criteria for assessing temperature risk to aquatic life. The 7-day mean temperature (maximum value of the 7-day moving average of the daily mean temperature) of 14.8?C was established as the upper threshold criterion for coho salmon and 17.0?C for steelhead trout. The risk assessment approach used by Sullivan et al. (2000) suggests that temperatures exceeding the above thresholds will cause 10% reduction in average fish growth compared to optimal conditions.

Guideline Reference:

An Analysis of the Effects of Temperature on Salmonids of the Pacific Northwest with Implications for Selecting Temperature Criteria

Spatial Representation:

Temperature was measured at four sites located on the mainstem of Stevens Creek. The highest temperatures were recorded at the most downstream location in July 2003. High temperatures exceeding the threshold for steelhead were measured in most parts of the creek with the exception of the upper reach.

Temporal Representation:

In 2002 and 2003 the SWAMP Program performed continuous monitoring of temperature at 15 minute intervals for periods of 1-2 weeks in each of three different seasons: winter wet season (3 sites), spring runoff season (1 site), and summer dry season (7 sites).

Environmental Conditions:

QAPP Information:

All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)