Final California 2012 Integrated Report( 303(d) List/305(b) Report)

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name:	Eureka Plain HU, Humboldt Bay
Water Body ID:	CAB1100000020020108173626
Water Body Type:	Bay & Harbor


DECISION ID	24033	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	PCBs (Polychlorinated biphenyls)
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)(2010)
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2025
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	PCBs in Humboldt Bay are being considered for removal from the 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 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 Section 303(d) List (i.e., sufficient justification to not de-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 two fish tissue samples exceed the COMM evaluation 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.

State Board Staff 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 24033, PCBs (Polychlorinated biphenyls)	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

23467

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

It is unknown if any of the 13 PCB samples collected in Humboldt Bay exceed the evaluation guideline. All of the samples were non-detect, but the detection limits are unknown. Samples were collected by the Wiyot Tribe and data are summarized by the Tribe (Wiyot 2007).

Data Reference:

Wiyot Tribe Water Quality Monitoring Program. Data for multiple parameters in McNultly Slough, Humboldt Bay Entrance, Indian Island, Mad River Slough, and Reservation Wetland, December 2004 to December 2006

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Per the Federal Register, Vol. 64, No. 216, pp. 61181 to 61196: The human health criterion for PCBs is 0.00017 ug/l for the protection of human health from consumption of aquatic organisms.

Guideline Reference:

Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants; States' Compliance - Revision of Polychlorinated Biphenyls (PCBs) Criteria. Federal Register. Volume 64, No. 216, pp. 61181 - 61196

Spatial Representation:

The data were collected from 4 sites in Humboldt Bay as follows: (1) Humboldt Bay Entrance just northeast of the east edge of the north jetty; (2) Indian Island just off one of the old pilings between the old industrial site on the Tribe's land and the middle channel of north Humboldt Bay; (3) Mad River Slough at the Samoa Boulevard Bridge over the Slough; and (4) the Reservation Wetland at the northeast corner of the Table Bluff Reservation. At the Reservation Wetland site, samples from December 2004 to February 2006 were collected from surface wetland waters. Starting in March 2006, two shallow-water monitoring wells were installed in the wetland and serve as the sample collection sites.

Temporal Representation:

Three samples were collected in March, July and November of 2006 for five of the areas sampled (Indian Island, Mad River Slough, & Bay Entrance, Wetland sites 1 & 2). The main Reservation wetland was sampled one time in May 2005.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to Wiyot Tribes Draft Quality Assurance Program Plan (QAPP) for Water Quality Assessment and Monitoring (McKernan et al. 2004). Specific detection limits are not specified.

QAPP Information Reference(s):

Draft Quality Assurance Program Plan (QAPP) for Water Quality Assessment and Monitoring. Table Bluff Reservation - Wiyot Tribe. Tribal Environmental Department. Prepared by Yurok Tribe Environmental Program. September 2004

Line of Evidence (LOE) for Decision ID 24033, PCBs (Polychlorinated biphenyls)	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

31735

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Both samples exceeded the guideline. Non-detect results were reported as zero (no method detection limits were provided) and were not included in the assessment. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for polychlorinated biphenyls in shellfish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site EUSB at Eureka Samoa Bridge, and another from HMBJ at Eureka Humboldt Bay Jetty.

Temporal Representation:

Samples were collected from Humboldt Bay as follows: EUSB on 1/23/2009 and from HMBJ on 1/22/2009.

Environmental Conditions:

QAPP Information:

Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituent

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 24033, PCBs (Polychlorinated biphenyls)	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

3669

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

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:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Unknown

Temporal Representation:

Unknown

Environmental Conditions:

Unknown

QAPP Information:

Unknown

QAPP Information Reference(s):


DECISION ID	31341	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	Arsenic
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 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 to assess protection of the commercial and sport fishing (COMM) beneficial use. 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 (i.e., sufficient justification to not 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) One of one sample exceeds the evaluation guideline, and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met, as a minimum of either (A) 16 samples, or (B) greater than or equal 2 exceedances of the objective with less than 16 samples is 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:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

State Board Staff 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 31341, Arsenic	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

31778

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

One of one sample exceeded the evaluation guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Ten percent of the total arsenic result was used to estimate of the amount of inorganic arsenic in the sample; this number was screened against the guideline. Two composite samples were collected from Humboldt Bay within one week, and thus, the average of the two composite samples was calculated, per USEPA 2001, resulting in a sample value of 0.0105 ppm.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for arsenic in shellfish tissue is 0.0052 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2004)

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Samples were collected in Humboldt Bay at: (EUSB) - Eureka Samoa Bridge and another from (HMBJ) - Eureka Humboldt Bay Jetty. One composite was made from fish at each of the two locations within Humboldt Bay.

Temporal Representation:

Samples were collected from Humboldt Bay as follows: EUSB on January 23, 2009 and from HMBJ on January 22, 2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	31527	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	Chlordane \| DDT (Dichlorodiphenyltrichloroethane) \| Dieldrin \| Heptachlor epoxide
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:	These pollutants are 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. Four lines of evidence are available to assess protection of the commercial and sport fishing (COMM) beneficial use. 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 (i.e., sufficient justification to not 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 two fish tissue samples evaluated for chlordane, DDT, and dieldrin exceed the COMM evaluation guideline. Zero of one fish tissue sample evaluated for hepatachlor epoxide exceeds the COMM evaluation guideline. These sample sizes are insufficient to determine with the power and confidence of the Listing Policy if standards are not met, as a minimum of either (A) 16 samples, or (B) greater than or equal 2 exceedances of the objective with less than 16 samples is 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:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

State Board Staff 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 31527, Multiple Pollutants	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

31731

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

None of the two samples did exceed the guideline. Non-detect results were reported as zero (no method detection limits were provided) and were not included in the assessment. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for dieldrin in shellfish tissue is 0.49 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site EUSB at Eureka Samoa Bridge, and another from HMBJ at Eureka Humboldt Bay Jetty.

Temporal Representation:

Samples were collected from Humboldt Bay as follows: EUSB on 1/23/2009 and from HMBJ on 1/22/2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 31527, Multiple Pollutants	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

31736

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

The one sample did not exceed the guideline. Non-detect results were reported as zero (no method detection limits were provided) and were not included in the assessment. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for heptachlor epoxide in shellfish tissue is 1.4 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 1999)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site EUSB at Eureka Samoa Bridge, and another from HMBJ at Eureka Humboldt Bay Jetty.

Temporal Representation:

Samples were collected from Humboldt Bay as follows: EUSB on 1/23/2009 and from HMBJ on 1/22/2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 31527, Multiple Pollutants	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

31738

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Chlordane result was calculated by summing the results for chlordane isomers: cis- and trans-nonachlor, alpha- and gamma-chlordane, and oxychlordane. Non-detect results were reported as zero (no method detection limits were provided) and were not included in the summation for a sample in the assessment.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for total chlordane in shellfish tissue is 6.0 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site EUSB at Eureka Samoa Bridge, and another from HMBJ at Eureka Humboldt Bay Jetty.

Temporal Representation:

Samples were collected from Humboldt Bay as follows: EUSB on 1/23/2009 and from HMBJ on 1/22/2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 31527, Multiple Pollutants	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

31730

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Both samples did not exceed the guideline. Non-detect results were reported as zero (no method detection limits were provided) and were not included in the assessment. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. The total DDTs were calculated as the sum of 4,4- and 2,4- isomers of DDT, DDE, and DDD).

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for total DDT in shellfish tissue is 23 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site EUSB at Eureka Samoa Bridge, and another from HMBJ at Eureka Humboldt Bay Jetty.

Temporal Representation:

Samples were collected from Humboldt Bay as follows: EUSB on 1/23/2009 and from HMBJ on 1/22/2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	23978	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	Indicator Bacteria
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)(2010)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Fecal indicator bacteria (which includes fecal coliform) are being considered for placement on the Section 303(d) list under Section 3.2 of the Listing Policy. Under this section a single line of evidence (LOE) is necessary to assess listing status. Three fecal coliform lines of evidence are available in the administrative record to assess indicator bacteria in this water body. There are two LOEs available to assess protection of the shellfish harvesting (SHELL) beneficial use and one LOE available to assess protection of the water contact recreation (REC-1) beneficial use. It should be noted that an additional LOE for total coliform data wasnot utilized in this decision because these bacteria are widespread in nature and occur in non-fecal sources such as soil and submerged wood. In accordance with Section 3.3 of the Listing Policy, a 4% exceedance rate shall be used to add waters to the List "if water quality monitoring was conducted April 1 through October 31 only". However, the data assessed in this decision include data collected during months outside the April - October range. Therefore, this pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy, using a 10% exceedance rate. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against adding this water segment-pollutant combination to the Section 303(d) list (i.e., sufficient justification to not 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) Twenty of 1,571 samples exceed the fecal coliform evaluation guideline for the SHELL beneficial use, and zero of 1,555 samples exceed the fecal coliform evaluation guideline for the REC-1 beneficial use. These exceedance rates do not exceed the evaluation guideline more than 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:	After review of the available data and information, North Coast RWQCB staff concludes that the water body-pollutant combination should not be placed on the Section 303(d) List because applicable water quality standards are not being exceeded.

State Board Staff 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 23978, Indicator Bacteria	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

33296

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

1555

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The samples were collected from fourteen sites in Humboldt Bay. One of the 1556 samples exceeded the evaluation guideline. The sample value exceeding the evaluation guideline was 500 MPN.

Data Reference:

Data for bacteria in Humboldt Bay, Jan. 2004-Aug. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteriological quality of waters of the North Coast Region shall not be degraded beyond natural background levels. In no case shall coliform concentrations in waters of the North Coast Region exceed the following: In waters designated for contact recreation (REC-1), the median fecal coliform concentration based on a minimum of not less than 5 samples for any 30-day period shall not exceed 50 MPN/ 100 ml, nor shall more than 10% of total samples during any 30-day period exceed 400 MPN / 100 ml. Water Quality Control Plan, North Coast Region (NCRWQCB 2011)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Beach posting is recommended when single sample fecal coliform levels exceed 400 MPN / 100 ml. Draft Guidance for Fresh Water Beaches" (DHS 2011).

Guideline Reference:

Draft Guidance for Fresh Water Beaches. Last Update: May 8, 2006. Initial Draft: November 1997. California Department of Public Health.

Spatial Representation:

The samples were collected from fourteen sites in Humboldt Bay. Those sites were WQ # 20, 21, 22, 24, 26, 28, 31, 33, 34, 43, 45, 51, 52, and 53.

Temporal Representation:

The samples were collected once a month from 2000 to 2010.

Environmental Conditions:

QAPP Information:

The samples were collected under the Management Plan For Commercial Shellfishing In Humboldt Bay, California. California Department of Public Health.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 23978, Indicator Bacteria	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

31815

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

1555

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Twenty of the 1555 samples sollected in Humboldt Bay exceeded the 43MPN/100ml objective.

Data Reference:

Data for bacteria in Humboldt Bay, Jan. 2004-Aug. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): At all areas where shellfish may be harvested for human consumption (SHELL), the fecal coliform concentration throughout the water column shall not exceed 43MPN/100ml for a 5-tube decimal dilution test or 49MPN/100ml when a three-tube decimal dilution test is used.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from fourteen sites in Humboldt Bay. Those sites were WQ # 20, 21, 22, 24, 26, 28, 31, 33, 34, 43, 45, 51, 52, and 53.

Temporal Representation:

The samples were collected once a month from 2000 to 2010.

Environmental Conditions:

QAPP Information:

The samples were collected under the Management Plan For Commercial Shellfishing In Humboldt Bay, California. California Department of Public Health.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 23978, Indicator Bacteria	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

24852

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 16 total coliform samples collected in Humboldt Bay exceed the 10,000 MPN / 100 ml objective. Samples range from less than 2 to more than 1,600 MPN / 100 ml. Samples were collected by the Wiyot Tribe and data are summarized by the Tribe (Wiyot 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The bacteriological quality of waters of the North Coast Region shall not be degraded beyond natural background levels. In no case shall coliform concentrations in waters of the North Coast Region exceed the following: In waters designated for contact recreation (REC-1), the median fecal coliform concentration based on a minimum of not less than five samples for any 30-day period shall not exceed 50 MPN* / 100 ml, nor shall more than 10% of total samples during any 30-day period exceed 400 MPN / 100 ml. At all areas where shellfish may be harvested for human consumption (SHELL), the fecal coliform concentration throughout the water column shall not exceed 43 MPN / 100 ml for a 5-tube decimal dilution test or 49 MPN / 100 ml when a three-tube decimal dilution is used. *Note: MPN is the most probable number of coliform units.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Per the "Draft Guidance for Fresh Water Beaches" (DHS 2006): Beach posting is recommended when single sample total coliform levels exceed 10,000 MPN / 100 ml.

Guideline Reference:

Draft Guidance for Fresh Water Beaches. Last Update: May 8, 2006. Initial Draft: November 1997. California Department of Public Health.

Spatial Representation:

Temporal Representation:

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to Wiyot Tribes Draft Quality Assurance Program Plan (QAPP) for Water Quality Assessment and Monitoring (McKernan et al. 2004).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 23978, Indicator Bacteria	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

23463

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 16 fecal coliform samples collected in Humboldt Bay exceed the 43 MPN / 100 ml objective. Samples range from non detect (with a detection limit of less than 2 MPN / 100 ml) to 23 MPN / 100 ml. Samples were collected by the Wiyot Tribe and data are summarized by the Tribe (Wiyot 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to Wiyot Tribes Draft Quality Assurance Program Plan (QAPP) for Water Quality Assessment and Monitoring (McKernan et al. 2004).

QAPP Information Reference(s):


DECISION ID	31528	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
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 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 to assess protection of the commercial and sport fishing (COMM) beneficial use. 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 (i.e., sufficient justification to not 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) One of two samples exceed the evaluation guideline, and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met, as a minimum of either (A) 16 samples, or (B) greater than or equal 2 exceedances of the objective with less than 16 samples is 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:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

State Board Staff 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 31528, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

31737

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

One sample result of 2.53 ppb did exceed the guideline. Non-detect results were reported as zero (no method detection limits were provided) and were not included in the assessment. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. The total PAHs were calculated as the potency equivalency concentration or the sum of the toxic equivalency factors multiplied by the concentrations of: Acenaphthene, Acenaphthylene, Anthracene, Benz[a]anthracene, Benzo[a]pyrene, Benzo[b]fluoranthene, Benzo[g,h,i]perylene, Benzo[k]fluoranthene, Dibenzo[a,h]anthracene, Chrysene, Fluoranthene, Fluorene, Indeno[1,2,3-c,d]pyrene, Phenanthrene, and Pyrene.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for polycyclic aromatic hydrocarbons in shellfish tissue is 1.1 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site EUSB at Eureka Samoa Bridge, and another from HMBJ at Eureka Humboldt Bay Jetty.

Temporal Representation:

Samples were collected from Humboldt Bay as follows: EUSB on 1/23/2009 and from HMBJ on 1/22/2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	22743	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	Dioxin Toxic Equivalents
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)(2010)
Revision Status	Original
Sources:	Industrial Point Sources \| Source Unknown \| Waste Storage/Storage Tank Leaks (above ground)
Expected TMDL Completion Date:	2025
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: (A) Dioxin toxic equivalents in Humboldt Bay are being considered for removal from the Section 303(d) List under Sections 4.5 and 4.6 of the Listing Policy. Nine lines of evidence are available in the administrative record to access this pollutant. These lines of evidence are discussed in detail below: (1) One of the lines of evidence (LOE 26439) is based on data compiled and assessed by the State Water Resources Control Board during the 2006 listing cycle and shows 14 out of 29 exceedances of the evaluation guideline used to interpret the water quality objective. Two lines of evidence (LOEs 21366 and 26044) are based on data assessed by the North Coast Regional Water Board during the current 2008 listing cycle and show 11 out of 41 exceedences of the evaluation guideline. Combined, there are 25 out of 70 exceedences of the evaluation guideline. The evaluation guideline is the dioxin toxic equivalent screening value for fish and shellfish tissue of 0.3 ng/kg by wet weight, which was developed by the Office of Environmental Health Hazard Assessment (Brodberg and Pollock 1999). The 0.3 ng/kg screening value is based on a low mean consumption value of fish of 21 g/day. (2) Four lines of evidence (LOEs 21425, 21430, 21383, and 21427) analyze sediment data from Humboldt Bay in relation to the Marine Habitat Beneficial Use. These lines of evidence show that the Marine Habitat Beneficial Use is protected due to 9 out of 117 exceedances of the Canadian Sediment Quality Guideline used to interpret the toxicity water quality objective, which are within the number of exceedances acceptable for a waterbody to be delisted per Table 4.1 of the Listing Policy. (3) The two remaining lines of evidence (LOEs 7810 and 21365) include data that are insufficient to make a decision regarding the dioxin impairment of Humboldt Bay. For LOE 7810, data could not be evaluated against the evaluation guideline as the data were presented in dry weight without a conversion factor, instead of wet weight. For LOE 21365, data quality was poor as information did not include sampling and analysis methods and quality assurance and control documents. (B) Based on readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of continuing to place this water segment-pollutant combination on the Section 303(d) List in the Water Limited Segments category (i.e., sufficient justification to not delist). 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 in all but one line of evidence (LOE 21365). (2) The data used satisfies the data quantity requirements of Section 6.1.5 of the Policy. (3) Combined, 25 out of 70 fish or shellfish tissue samples exceed the 0.3 ng/kg OEHHA screening value used to interpret the toxicity water quality objective for the protection of the Commercial and Sport Fishing Beneficial Use, 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:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

26439

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Dissolved

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

This line of evidence (LOE) is a revision of LOE number 1 that was originally prepared by the State Water Resources Control Board for the 2006 303(d) List. The revision is necessary in order to state the proper evaluation guideline of 0.3 ng/kg instead of 3 ng/kg, and in order to provide references to the data used in the 2006 assessment.

As analyzed by the State Water Board, 14 out of 29 samples exceed the evaluation guideline. Crab, mussel, oyster, and sculpin samples were taken in the North and South Bays from 3/24/02 to 10/25/02. Data was originally cited as coming from Smith (2006). Available data can be found in the spreadsheet prepared by the State Water Resources Control Board (SWRCB 2006).

Data Reference:

Data for Dioxins and Furans in Humboldt Bay, March to October 2002. Compiled by the State Water Resources Control Board.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Per the Office of Environmental Health Hazard Assessment (Brodberg and Pollack 1999): The dioxin toxic equivalent screening value for fish and shellfish tissue is 0.3 ng/kg by wet weight. It is appropriate for the 2,3,7,8-tetracholorodibenzodioxin (TCDD) toxic equivalent concentration (TEQ) for mammals to be compared against this screening value. The TCDD equivalent is the sum of the concentrations of chlorinated dibenzodioxins (2,3,7,8-CDDs) and chlorinated dibenzofurans (2,3,7,8-CDFs) multiplied by their respective toxicity factors.

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Two sample locations (Lappe S2) in the southern section of the Bay, south of the mouth, and 12 samples in the northern section of Humboldt Bay. Some samples taken in close proximity were averaged (pursuant to Section 6.1.5.2 of the Policy).

Temporal Representation:

Samples were taken from 3/24/02 to 10/25/02.

Environmental Conditions:

QAPP Information:

Sierra Pacific Industries Humboldt Bay.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

26044

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

None of the 16 fish tissue TCDD equivalent samples (wet weight) collected in Mad River Slough exceed the evaluation guideline. The TCDD equivalent values range from 0.03 ng/kg to 0.29 ng/kg. Samples were collected by Geomatrix on behalf of Sierra Pacific Industries, Arcata Division Sawmill as fish fillets. Data are summarized by Geomatrix (2006).

Data Reference:

Revised Supplement to Scoping Ecological and Off-site Human Health Risk Assessment. Sierra Pacific Industries. Arcata Divsion Sawmill. Arcata, CA. Project No. 9329.000, Task 20

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Samples were collected from 15 sites in the Mad River Slough, which drains to Humboldt Bay.

Temporal Representation:

Data was collected between March 16, 2005 and May 10, 2005.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storm events, etc.) that may have impacted these data.

QAPP Information:

Sampling and testing methods are described by Geomatrix (2006). The TEQs were calculated using World Health Organization mammalian toxic equivalent factors (2003), but were updated to the WHO 2005 values by Regional Water Board Staff.

QAPP Information Reference(s):

Revised Supplement to Scoping Ecological and Off-site Human Health Risk Assessment. Sierra Pacific Industries. Arcata Divsion Sawmill. Arcata, CA. Project No. 9329.000, Task 20

Line of Evidence (LOE) for Decision ID 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

21430

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Not Recorded

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Chemical monitoring of sediments

Data Used to Assess Water Quality:

None of the 60 sediment TCDD equivalent samples (dry weight) collected in Humboldt Bay exceeded the evaluation guideline. The TCDD equivalent values range from 0.001 ng/kg to 0.75 ng/kg. Samples were collected by Toxscan Inc. and Kinnetic Laboratories Inc. Data are summarized in the "Chemical Analysis, Toxicity Evaluation and Bioaccumulation Exposure of Sediments from Humboldt Bay: Baseline Survey III, Fiscal Year 1995" (Toxscan and Kinnetic 1996).

Data Reference:

Chemical Analysis, Toxicity Evaluation and Bioaccumulation Exposure of Sediments from Humboldt Bay: Baseline Survey III, Fiscal Year 1995. Final Report. Prepared for: U.S. Army Engineering District San Francisco Corps of Engineers. February 1996

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Per the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life (CCME 2001): The Interim Sediment Quality Guideline for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans is 0.85 ng/kg (dry weight) expressed on a toxic equivalent unit basis using toxic equivalent factors for fish.

Guideline Reference:

Canadian Sediment Quality Guidelines for the Protection of Aquatic Life: Polychlorinated dioxins and furans (PCDD/Fs). In: Canadian Environmental Quality Guidelines, 1999, Canadian Council of Ministers of the Environment, Winnipeg. Excerpt from Publication No. 1299; ISBN1-896997-34-1

Spatial Representation:

Composite samples were collected at 4 sites in Humboldt Bay, as follows: (1) at Eureka Upper Channel, (2) at Samoa Turning Basin, (3) at Fields Landing Lower Channel and Turning Basin, and (4) at Eureka Upper Channel Extension.

Temporal Representation:

Samples were collected April 1 to 4, 1995.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality control was conducted as specified in Toxscan Inc. and Kinnetic Laboratories Inc. (1996). Although it is not specified if dioxin data is reported in dry or wet weight, EPA Method 8290 dictates reporting as dry weight, and it is thus assumed that all dioxin data are in dry weight.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

21427

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Not Recorded

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Chemical monitoring of sediments

Data Used to Assess Water Quality:

None of the 6 sediment TCDD equivalent samples (dry weight) collected in Humboldt Bay exceeded the evaluation guideline. The TCDD equivalent values range from 0.01 ng/kg to 0.17 ng/kg. Samples were collected by Toxscan Inc. and Kinnetic Laboratories Inc. Data are summarized in the "Chemical Analysis, Toxicity Evaluation and Bioaccumulation Exposure of Sediments from Humboldt Bay: Baseline Survey II, Fiscal Year 1994" (Toxscan and Kinnetic 1994).

Data Reference:

Chemical Analysis, Toxicity Evaluation and Bioaccumulation Exposure of Sediments from Humboldt Bay: Baseline Survey II, Fiscal Year 1994. Final Report. Prepared for U.S. Army Engineering District San Francisco Corps of Engineers. November 1994

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Composite samples were collected at 3 sites in Humboldt Bay, as follows: (1) at Eureka Upper Channel, (2) at Samoa Turning Basin, and (3) at Fields Landing Lower Channel and Turning Basin.

Temporal Representation:

Samples were collected April 1 and 2, 1994.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality control was conducted as specified in Toxscan Inc. and Kinnetic Laboratories Inc. (1994).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

7810

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

It is unknown if any of the 4 TCDD equivalent samples collected in Humboldt Bay exceed the evaluation guideline as data were presented as dry weight and the evaluation guideline is in wet weight. Since no conversion factor for calculating dry to wet weight was given in the data, the data could not be evaluated against the evaluation guideline. TCDD equivalent values range from 0.11 to 10.9 pg/g. TCDD equivalent values were analyzed from the tissue of the Bay Mussel (Mytilus edulus), a species endemic to Humboldt Bay. Samples were collected by Regional Water Board staff and data are summarized in a preliminary report (Rodriguez 1989).

Data Reference:

Preliminary Report on Mussel Collections and Analyzes for Dioxins and Furans along the North Coast from the Mouth of San Francisco Bay to Crescent City. California Regional Water Quality Control Board, North Coast Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Samples were collected from 4 sites in Humboldt Bay as follows: (1) Mad River Slough Oyster Bed #1; (2) Bird Island West Side; (3) inside the North Jetty at the interface between the dolos and rock; and (4) in the Eureka Channel, Samoa Bridge pier, southeast side.

Temporal Representation:

One sample was collected from each site on June 5, 6, or 7, 1989.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storm events, etc.) that may have impacted these data.

QAPP Information:

The procedures used to collect and analyze the data are summarized by Rodriguez (1989). No project specific quality control spikes or duplicates were collected due to funding constraints.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

21382

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Not Recorded

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Nine of the 45 sediment TCDD equivalent samples (dry weight) collected in Humboldt Bay exceeded the evaluation guideline. The TCDD equivalent values range from <0.0002 ng/kg to 4.8 ng/kg. Samples were collected by the Soil/Water/Air Protection Enterprise (SWAPE), and data are summarized in the SWAPE attachment to Humboldt Baykeeper's letter of February 28, 2007 (Humboldt Baykeeper 2007).

Data Reference:

Letter from Michelle D. Smith of Humboldt Baykeeper to Bruce Gwynne of the North Coast Regional Water Quality Control Board dated February 28, 2007, regarding Data Solicitation, 2008 Clean Water Act 303(d) List of Impaired Waters

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at 3 sites in Humboldt Bay, as follows: 2 sites in the mud flats of Humboldt Bay (S-8 & S-9), and 1 site in Hookton Slough (S-10).

Temporal Representation:

Samples collected April 18, 2006.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality control was conducted in accordance with the Soil/Water/Air Protection Enterprise's "Sampling and Analysis Plan" (Humboldt Baykeeper 2006).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

21366

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Eleven of the 25 shellfish tissue TCDD equivalent samples (wet weight) collected in Humboldt Bay exceed the evaluation guideline. The TCDD equivalent values range from 0.1 ng/kg to 4.3 ng/kg. Samples were collected by EnviroNet and ENVIRON on behalf of Sierra Pacific Industries, Arcata Division Sawmill in commercially grown oysters and mussels from Humboldt Bay. Data are summarized by EnviroNet and ENVIRON (2003).

Data Reference:

Evaluation of the Results of Dioxin and Other Chemical Testing of Commercial Oyster Beds in Humboldt Bay, California From June and October 2002. Prepared by EnviroNet and ENVIRON for Sierra Pacific Industries

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Samples were collected from 10 sites in Humboldt Bay as follows: (1) at Coast Seafood, Inc., East Bay Bed 6-2; (2) at Coast Seafood, Inc., East Bay Bed 1-2; (3) at North Bay Shellfish Company Bed; (4) at North Bay Shellfish Company wet storage oyster; (5) at Coast Seafoods, Inc., Mad River Bed 7-1; (6) at Coast Seafoods, Inc., Mad River Bed 7-2; (7) at Coast Seafoods, Inc. Sand Island North Bed; (8) at Coast Seafoods, Inc., Sand Island North Bed 1-2; (9) at Coast Seafoods, Inc., Bird Island North Bed; and (10) at at Coast Seafoods, Inc., Bird Island South Bed.

Temporal Representation:

Data was collected June 21 and October 21, 2002.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storm events, etc.) that may have impacted these data.

QAPP Information:

Sampling and testing methods are described by EnvironNet and ENVIRON (2003). The TEQs were calculated using World Health Organization mammalian toxic equivalent factors from 1998. Non-detect data were represented using one half the congener-specific detection limit or estimated maximum possible concentrations reported by the laboratory.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

21365

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

None of the 34 shellfish tissue TCDD equivalent samples (wet weight) collected in Humboldt Bay exceed the evaluation guideline. The TCDD equivalent values range from 0 to 0.170 ng/kg. Samples were collected by the California Department of Health Services and data are summarized in their letter of March 3, 2006 (DHS 2006).

Data Reference:

Letter from Michael F. Hernandez of the California Department of Health Services, Food and Drug Branch to Mary Middleton of Pacific Shellfish Institute dated March 3, 2006. State of California Health and Human Services Agency, Department of Health Services

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Samples were collected from 7 sites in the northern portion of Humboldt Bay, above Indian Island.

Temporal Representation:

Data was collected April 15-18, 2002.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storm events, etc.) that may have impacted these data.

QAPP Information:

The quality assurance and quality control measures used to collect the samples is unknown. Data were presented as TEQs for "dioxins in molluscan shellfish" and it is unknown which specific dioxin and/or furan congeners were present and used to calculate the TEQ.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 22743, Dioxin Toxic Equivalents	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

21425

Pollutant:

Dioxin Toxic Equivalents

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Not Recorded

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Chemical monitoring of sediments

Data Used to Assess Water Quality:

None of the 6 sediment TCDD equivalent samples (dry weight) collected in Humboldt Bay exceeded the evaluation guideline. The TCDD equivalent values range from 0.01 ng/kg to 0.12 ng/kg. Samples were collected by Toxscan Inc. and Kinnetic Laboratories Inc. Data are summarized in the "Chemical Analysis, Toxicity Evaluation and Bioaccumulation Testing of Sediments from Humboldt Bay: Baseline Survey 1, Fiscal Year 1993" (Toxscan and Kinnetic 1994).

Data Reference:

Chemical Analysis, Toxicity Evaluation and Bioaccumulation Testing of Sediment from Humboldt Bay: Baseline Survey I, Fiscal Year 1993. Final Report. Prepared for US. Army Engineering District San Francisco Corps of Engineers. Final Revision September 1994

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Composite samples were collected at 3 sites in Humboldt Bay, as follows: (1) at Eureka Upper Channel, (2) at Samoa Turning Basin, and (3) at Fields Landing Lower Channel and Turning Basin.

Temporal Representation:

Samples were collected October 30 to November 1, 1992.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality control was conducted as specified in Toxscan Inc. and Kinnetic Laboratories Inc. (1994).

QAPP Information Reference(s):


DECISION ID	26675	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	2,3,5,6-Tetrachlorophenol
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)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Tetrachlorophenol in Humboldt Bay 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. It is unknown whether any of the 4 Humboldt Bay fish tissue samples analyzed for tetrachlorophenol exceed the objective, as there is no suitable evaluation guideline relating potential public health concerns from ingesting fish tissue containing tetrachlorophenol. Samples ranged from 2.75 ppb to 6.00 ppb. Based on the readily available data and information, the weight of evidence indicates that there is insufficient information available to determine if it is appropriate to place this water segment-pollutant combination on the Section 303(d) list in the Water Quality Limited Segments category.

Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 26675, 2,3,5,6-Tetrachlorophenol	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

21443

Pollutant:

2,3,5,6-Tetrachlorophenol

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

BIOLOGICAL MONITORING

Data Used to Assess Water Quality:

It is unknown whether any of the 4 Humboldt Bay fish tissue samples analyzed for tetrachlorophenol exceed the objective, as there is no suitable evaluation guideline relating potential public health concerns from ingesting fish tissue containing tetrachlorophenol. Samples ranged from 2.75 ppb to 6.00 ppb. These samples were collected by the California State Mussel Watch Program. Data are summarized in the "California State Mussel Watch Ten Year Data Summary 1977-1987" (SWRCB 1988).

Data Reference:

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from 4 sites in Humboldt Bay. These sites are as follows: (1) at Mad River Slough, (2) at Arcata Ruin, (3) at Samoa Bridge West, and (4) at Woodley Island.

Temporal Representation:

Samples were collected on February 15, 1984.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to the protocols provided by the CA State Mussel Watch Program (California State Mussel Watch 1988, Appendix A).

QAPP Information Reference(s):

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board


DECISION ID	22095	Region 1
Eureka Plain HU, Humboldt Bay

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)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Cadmium in Humboldt Bay 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 80 Humboldt Bay tissue samples analyzed for cadmium exceed the objective. Cadmium values ranged from 0.03 ppm to 2.33 ppm. 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 (i.e., sufficient justification to not 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) None of the 80 samples exceed 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:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 22095, Cadmium	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

9109

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

BIOLOGICAL MONITORING

Data Used to Assess Water Quality:

None of the 80 Humboldt Bay fish tissue samples analyzed exceeded the screening value for cadmium. These samples were collected by the California State Mussel Watch Program. Data are summarized in the "California State Mussel Watch Data Summary 1977-1997" (SWRCB 1988).

Data Reference:

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board

State Mussel Watch Program Data 1977-2000: trace elements by wet weight. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): 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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Water Board.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 3 mg/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

The samples were collected from 16 sites in Humboldt Bay. These sites are as follows: (1) at Mad River Slough, (2) at Arcata Ruin, (3) at Samoa Bridge West, (4) Samoa Bridge East, (5) at Woodley Island, (6) at Eureka STP, (6) at Eureka STP Outfall, (7) Eureka STP Control, (8) C Street, (9) J Street, (10) H Street, (11) Eureka Channel, (12) Louisiana Pacific Dock, (13) EDA Dock, (14) Fields Landing, (15) E Street and, (16) Halberson Shore

Temporal Representation:

The samples were collected from 1980 to 1997.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to the protocols provided by the CA State Mussel Watch Program (California State Mussel Watch 1988, Appendix A).

QAPP Information Reference(s):

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board


DECISION ID	22105	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	Chromium
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)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Chromium in Humboldt Bay 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. It is unknown whether any of the 6 Humboldt Bay fish tissue samples analyzed for chromium exceed the objective, as there is no suitable evaluation guideline relating potential public health concerns from ingesting fish tissue containing cadmium. Chromium values ranged from 0.6 ppm to 0.88 ppm. Based on the readily available data and information, the weight of evidence indicates that there is insufficient information available to determine if it is appropriate to place this water segment-pollutant combination on the Section 303(d) list in the Water Quality Limited Segments category.

Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 22105, Chromium	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

9110

Pollutant:

Chromium (total)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

BIOLOGICAL MONITORING

Data Used to Assess Water Quality:

It is unknown whether any of the 6 Humboldt Bay fish tissue samples analyzed for chromium exceed the objective, as there is no suitable evaluation guideline relating potential public health concerns from ingesting fish tissue containing chromium. Chromium values ranged from 0.73 ppm to 1.87 ppm. These samples were collected by the California State Mussel Watch Program. Data are summaried in the "California State Mussel Watch Ten Year Data Summary 1977-1987" (SWRCB 1988).

Data Reference:

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from 6 sites in Humboldt Bay. These sites are as follows: (1) at Mad River Slough, (2) at Arcata Ruin, (3) at Samoa Bridge West, (4) at Woodley Island, (5) at Eureka STP, and (6) at Eureka.

Temporal Representation:

The samples were collected during 1 site visit on February 15, 1984.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to the protocols provided by the CA State Mussel Watch Program (California State Mussel Watch 1988, Appendix A).

QAPP Information Reference(s):

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board


DECISION ID	22183	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	Mercury
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)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Mercury in Humboldt Bay 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 6 samples exceed the evaluation guideline used to interpret the toxicity water quality objective. The evaluation guideline is taken from the "General Protocol for Sport Fishing Sampling and Analysis" (Gassel & Broberg 2005), which includes a screening value for mercury concentrations that pose a potential public health concern of 0.08 ppm wet weight. This is a conservative screening value based upon a woman of childbearing age who consumes 12 meals a month. This conservative guideline was used because it is known that Humboldt Bay is used by the Wyott Tribe for subsistence fishing. The mercury samples ranged from 0.036 ppm to 0.045 ppm. 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 (i.e., sufficient justification to not 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) None of the 6 samples exceed the evaluation guideline, 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:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 22183, Mercury	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

9108

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Cultural/Traditional Rights

Number of Samples:

Number of Exceedances:

Data and Information Type:

BIOLOGICAL MONITORING

Data Used to Assess Water Quality:

None of the 6 Humboldt Bay fish tissue samples analyzed for mercury exceed the evaluation guideline. The mercury values ranged from 0.036 ppm to 0.045 ppm. These samples were collected by the California State Mussel Watch Program. Data are summaried in the "California State Mussel Watch Ten Year Data Summary 1977-1987" (SWRCB 1988).

Data Reference:

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Per the "General Protocol for Sport Fishing Sampling and Analysis" (Gassel & Broberg 2005): The screening value for mercury concentrations that pose a potential public health concern is 0.08 ppm wet weight. This is a conservative screening value based upon a woman of childbearing age who consumes 12 meals a month.

Guideline Reference:

General Protocol for Sport Fish Sampling and Analysis. Pesticide and Environmental Toxicology Branch. Office of Environmental Health Hazard Assessment. California Environmental Protection Agency. December 2005

Spatial Representation:

Temporal Representation:

The samples were collected during 1 site visit on February 15, 1984.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to the protocols provided by the CA State Mussel Watch Program (California State Mussel Watch 1988, Appendix A).

QAPP Information Reference(s):

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board


DECISION ID	23979	Region 1
Eureka Plain HU, Humboldt Bay

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)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Dissolved oxygen in Humboldt Bay 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. Eleven out of 103 dissolved oxygen 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 (i.e., sufficient justification to not 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) Eleven out of 103 samples exceed the evaluation guideline, and this does not exceed the allowable frequency of 17 per the 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:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 23979, Oxygen, Dissolved	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

23451

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Marine Habitat

Aquatic Life Use:

Cold Freshwater Habitat | Wildlife Habitat

Number of Samples:

103

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Eleven of the 103 monthly dissolved oxygen (DO) averages (by individual monitoring locations) exceed the objective. In other words, they were below the 6.0 mg/l minimum objective. The majority of these (10 of 11) occurred at the Reservation Wetland site. The average of the 11 exceedances is 3.9 mg/l. There were no exceedances of the 50th percentile or 90th percentile objectives. The lower 50th percentile (of average monthly DO) for all data in Humboldt Bay was 7.71 mg/l. The lower 90th percentile (of average monthly DO) for all data in Humboldt Bay was 6.96 mg/l. Samples were collected by the Wiyot Tribe and data are summarized by the Tribe (Wiyot 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The minimum dissolved oxygen objective is 6.0 mg/l. The 90% lower limit dissolved oxygen objective is 6.0 mg/l. The 50% lower limit dissolved oxygen objective is 7.0 mg/l. The 90% and 50% lower limits represent the 90/50 percentile values for a calendar year. 90% or 50% or more of the values must be greater than or equal to the lower limit.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

At Humboldt Bay Entrance, DO samples were collected every two weeks from December 2004 to December 2006 during the last hour of the incoming tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used.

At Indian Island, DO samples were collected every two weeks from December 2004 to September 2006 during the mid tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used. Also at Indian Island, DO samples were collected at 15 minute intervals from January 13, 2006 to March 9, 2006 and from September 22, 2006 to December 22, 2006.

At Mad River Slough, DO samples were collected every two weeks from December 2004 to December 2006 during the outgoing tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used.

At the Reservation Wetland, DO samples were collected every two weeks during the wet season from December 2004 to February 2006. DO samples were also collected every two weeks from March 2006 to December 2006. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to Wiyot Tribes Draft Quality Assurance Program Plan (QAPP) for Water Quality Assessment and Monitoring (McKernan et al. 2004).

QAPP Information Reference(s):


DECISION ID	22704	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	Pentachlorophenol (PCP)
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)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Pentachlorophenol in Humboldt Bay 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. It is unknown whether any of the 4 Humboldt Bay fish tissue samples analyzed for pentachlorophenol exceed the objective, as there is no suitable evaluation guideline relating potential public health concerns from ingesting fish tissue containing pentachlorophenol. Samples ranged from 20.52 ppb to 153.6 ppb. Based on the readily available data and information, the weight of evidence indicates that there is insufficient information available to determine if it is appropriate to place this water segment-pollutant combination on the Section 303(d) list in the Water Quality Limited Segments category.

Regional Board Decision Recommendation:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 22704, Pentachlorophenol (PCP)	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

21422

Pollutant:

Pentachlorophenol (PCP)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

BIOLOGICAL MONITORING

Data Used to Assess Water Quality:

It is unknown whether any of the 4 Humboldt Bay fish tissue samples analyzed for pentachlorophenol exceed the objective, as there is no suitable evaluation guideline relating potential public health concerns from ingesting fish tissue containing pentachlorophenol. Samples ranged from 20.52 ppb to 153.6 ppb. These samples were collected by the California State Mussel Watch Program. Data are summarized in the "California State Mussel Watch Ten Year Data Summary 1977-1987" (SWRCB 1988).

Data Reference:

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from 4 sites in Humboldt Bay. These sites are as follows: (1) at Mad River Slough, (2) at Arcata Ruin, (3) at Samoa Bridge West, and (4) at Woodley Island.

Temporal Representation:

The samples were collected during 1 site visit on February 15, 1984.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to the protocols provided by the CA State Mussel Watch Program (California State Mussel Watch 1988, Appendix A).

QAPP Information Reference(s):

California State Mussel Watch Ten Year Data Summary 1977-1987. Water Quality Monitoring Report No. 87-3. State Water Resources Control Board


DECISION ID	20592	Region 1
Eureka Plain HU, Humboldt Bay

Pollutant:	Temperature, water
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)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board Conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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. It is unknown if any of the 11,248 temperature samples collected in Humboldt Bay exceed the objective. There is not sufficient information available to determine the natural receiving water temperature of marine waters and Regional Water Board are unable to evaluate compliance with the 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 (i.e., sufficient justification to not list). This conclusion is also 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) 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:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 20592, Temperature, water	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

5548

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

It is unknown if any of the 11,248 temperature samples collected in Humboldt Bay exceed the objective. The samples collected were ambient water samples collected in Humboldt Bay. The bay drains to the ocean every 6 hours or so. There is not sufficient information available to determine the natural receiving water temperature of the marine waters of Humboldt Bay and thus, Regional Water Board staff are unable to evaluate compliance with the objective. Samples were collected by the Wiyot Tribe and data are summarized by the Tribe (Wiyot 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Thermal Plan (SWRCB 1972): For existing discharges: (1) Elevated temperature waste discharges shall comply with limitations necessary to assure protection of beneficial uses. For new discharges: (1) Elevated temperature waste discharges shall comply with limitations necessary to assure protection of beneficial uses. The maximum temperature of waste discharges shall not exceed the natural temperature of the receiving waters by more than 20°F. (2) Thermal waste discharges having a maximum temperature greater than 4°F above the natural temperature of the receiving water are prohibited. And per the Basin Plan (NCRWQCB 2007): 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. At no time or place shall the temperature of any COLD water be increased by more than 5°F above natural receiving water temperature.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays and Estuaries of California (Thermal Plan). State Water Resources Control Board

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The temperature data were collected from 4 sites in Humboldt Bay as follows: (1) Humboldt Bay Entrance just northeast of the east edge of the north jetty; (2) Indian Island just off one of the old pilings between the old industrial site on the Tribe's land and the middle channel of north Humboldt Bay; (3) Mad River Slough at the Samoa Boulevard Bridge over the Slough; and (4) the Reservation Wetland at the northeast corner of the Table Bluff Reservation. At the Reservation Wetland site, samples from December 2004 to February 2006 were collected from surface wetland waters. Starting in March 2006, two shallow-water monitoring wells were installed in the wetland and serve as the sample collection sites.

Temporal Representation:

At Humboldt Bay Entrance, temperature samples were collected every two weeks from December 2004 to December 2006 during the last hour of the incoming tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used. At Indian Island, temperature samples were collected every two weeks from December 2004 to September 2006 during the mid tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used. Also at Indian Island, temperature samples were collected at 15 minute intervals from January 13, 2006 to March 9, 2006 and from September 22, 2006 to December 22, 2006. At Mad River Slough, temperature samples were collected every two weeks from December 2004 to December 2006 during the outgoing tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used. At the Reservation Wetland, temperature samples were collected every two weeks during the wet season from December 2004 to February 2006 during the wet season. Temperature samples were also collected every two weeks from March 2006 to December 2006. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to Wiyot Tribes Draft Quality Assurance Program Plan (QAPP) for Water Quality Assessment and Monitoring (McKernan et al. 2004).

QAPP Information Reference(s):


DECISION ID	24270	Region 1
Eureka Plain HU, Humboldt Bay

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)(2010)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Water Board conclusion: This pollutant was considered for placement on the section 303 (d) list in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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. Fifty-one of the 330 pH 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 (i.e., sufficient justification to not 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) Fifty-one of the 330 samples exceed the objective, and this does not exceed the allowable frequency of 55 per the binomial distribution described in Section 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:	No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

State Board Staff 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 24270, pH	Region 1
Eureka Plain HU, Humboldt Bay

LOE ID:

23470

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Marine Habitat

Number of Samples:

330

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Over 13,300 pH samples were collected from Humboldt Bay from the continous data recorders & grab samples. Daily averages were calculated for each monitoring location. Of the daily averages, 51 of the 330 pH values exceed the objective (they were below the minimum objective of 7.0). All of these exceedances were collected at the Reservations wetland sites. These exceedances ranged from 5.7 to 6.97, and averaged 6.5. It is possible, but unknown, if these wetlands are somewhat acidic due to naturally high levels of dissolved organic carbon. None of the pH measurements (or daily pH averages) exceeded the high pH objective of 8.5. Samples were collected by the Wiyot Tribe and data are summarized by the Tribe (Wiyot 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007, p. 3-8.00): The maximum pH objective is 8.5. The minimum pH objective is 7.0. Changes in normal ambient pH levels shall not exceed 0.2 units in waters with designated marine (MAR) beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

At Humboldt Bay Entrance, pH samples were collected every two weeks from December 2004 to December 2006 during the last hour of the incoming tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used.

At Indian Island, pH samples were collected every two weeks from December 2004 to September 2006 during the mid tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used. Also at Indian Island, pH samples were collected at 15 minute intervals from January 13, 2006 to March 9, 2006 and from September 22, 2006 to December 22, 2006.

At Mad River Slough, pH samples were collected every two weeks from December 2004 to December 2006 during the outgoing tide. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used.

At the Reservation Wetland, pH samples were collected every two weeks during the wet season from December 2004 to February 2006 during the wet season. pH samples were also collected every two weeks from March 2006 to December 2006. The sonde was deployed for approximately 15 minutes, with a 3 - 5 minute equilibration period and an 8 - 10 minute sampling period with 4 second intervals. The average of the daily data was used.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected according to Wiyot Tribes Draft Quality Assurance Program Plan (QAPP) for Water Quality Assessment and Monitoring (McKernan et al. 2004).

QAPP Information Reference(s):