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TMDL Document for CALLEGUAS CREEK, ITS TRIBUTARIES AND MUGU LAGOON METALS TMDL

TMDL ID: 33680 TMDL Name: CALLEGUAS CREEK, ITS TRIBUTARIES AND MUGU LAGOON METALS TMDL
State/Tribe: California TMDL Date: 03/26/2007
EPA Action: EPA Approved Comments: SEE CALIFORNIA TOXICS RULE AT HTTP://WWW.EPA.GOV/WATERSCIENCE/STANDARDS/CTR/TOXIC.PDF FOR BASIS OF MERCURY TARGETS

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TMDL Pollutant: Copper

Total Waste Load Allocation:      Total Load Allocation:
Explicit Margin Of Safety:      Implicit Margin Of Safety: Not Reported
Units for Total Waste Load Allocation and Total Load Allocation:      TMDL Pollutant Source Type: Point/Nonpoint Source
TMDL End Point: (IN UG DISSOLVED COPPER/L) DRY WEATHER/WET WEATHER/SEDIMENT TARGET PPB MUGU LAGOON: 3.1*WER(1)/4.8*WER(1)/34000 CALLEGUAS CK 2: 3.1*WER(1)/4.8*WER(1)/34000 CALLEGUAS CK 3: 25.9/26.3/NA(2) REVOLON/BEARDSLEY: 3.1*WER(1)/4.8WER(1)/NA(2) CONEJO: 27.0/41.6/NA(2) ARROYO SIMI/LAS POSAS: 29.3/29.8/NA(2) 1 THE WER HAS A NUMERIC VALUE OF 1.0. A WER STUDY FOR MUGU LAGOON, LOWER CALLEGUAS CREEK AND REVOLON SLOUGH HAS BEEN SUBMITTED TO THE REGIONAL BOARD AND IS CURRENTLY UNDER REVIEW BY REGIONAL BOARD AND USEPA STAFF. IF A WER OR SSO FOR COPPER IS APPROVED, THE NUMERIC TARGET IN THIS TMDL SHALL BE SET IN ACCORDANCE WITH THE APPROVED WER OR SSO, OR THE REGIONAL BOARD WILL RECONSIDER REVISION TO THE NUMERIC TARGETS BASED ON THE APPROVED WER OR SSO. 2 SEDIMENT TARGETS WERE NOT SELECTED AS ALTERNATIVE TARGET FOR THIS REACH AS IT IS NOT ON THE 303(D) LIST.

NPDES Allocation for Pollutant: Copper
NPDES ID Other Non PCS Identification Waste Load Allocation Units
CA0053597

.07
LBS/DAY
CA0056294

.07
LBS/DAY


Listed Water Causes of Impairment for Copper
Click on the underlined Waterbody ID for a Waterbody Report. Click on the underlined "Waterbody Map" literal for a map of the Assessment Unit.
Waterbody ID Waterbody Name Map Cycles Listed Cause(s) of Impairment Addressed
CA404.0200R CALLEGUAS R1 CALLEGUAS CREEK REACH 1 (WAS MUGU LAGOON ON 1998 303(D) LIST) Data Unavailable 2002 Copper
CA404.0220R CALLEGUAS R2 CALLEGUAS CREEK REACH 2 (ESTUARY TO POTRERO RD- WAS CALLEGUAS CREEK REACHES 1 AND 2 ON 1998 303D LIST) Data Unavailable 2002 Copper

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TMDL Pollutant: Mercury

Total Waste Load Allocation: .051      Total Load Allocation:
Explicit Margin Of Safety:      Implicit Margin Of Safety: Y
Units for Total Waste Load Allocation and Total Load Allocation: UG/L      TMDL Pollutant Source Type: Point/Nonpoint Source
TMDL End Point: THERE IS INSUFFICIENT INFORMATION TO ASSIGN MASS BASED WLAS TO THESE SOURCES. THEREFORE CONCENTRATION-BASED WASTE LOADS ALLOCATIONS ARE SET TMDL ELEMENT CALLEGUAS CREEK WATERSHED METALS AND SELENIUM TMDL EQUAL TO 0.051 (UG/L) FOR OTHER NPDES DISCHARGERS BASED ON THE CTR WATER COLUMN TARGET FOR PROTECTION OF HUMAN HEALTH FROM CONSUMPTION ORGANISM ONLY. MERCURY TARGETS A) FISH TISSUE (HUMAN HEALTH): 0.3 MG/KG WET WEIGHT B) FISH TISSUE (WILDLIFE): V TROPHIC LEVEL (TL) 31 < 50 MM: 0.03 MG/KG WET WEIGHT TMDL ELEMENT CALLEGUAS CREEK WATERSHED METALS AND SELENIUM TMDL V TL3 50-150MM: 0.05 MG/KG WET WEIGHT V TL3 150350MM: 0.1 MG/KG WET WEIGHT C) BIRD EGG (WILDLIFE): LESS THAN 0.5 MG/KG WET WEIGHT D) WATER COLUMN TARGET: 0.051 UG TOTAL MERCURY/L 1 TROPIC LEVEL 3: PREDATORS (E.G., MINNOWS, SUNFISH) ON TROPIC LEVEL 2 ORGANISM (E.G., COPEPODS AND WATER FLEAS)

NPDES Allocation for Pollutant: Mercury
NPDES ID Other Non PCS Identification Waste Load Allocation Units
CA0053597

.03
LBS/MONTH
CA0056294

.023
LBS/MONTH
CAS004002

.18
LBS/MONTH


Listed Water Causes of Impairment for Mercury
Click on the underlined Waterbody ID for a Waterbody Report. Click on the underlined "Waterbody Map" literal for a map of the Assessment Unit.
Waterbody ID Waterbody Name Map Cycles Listed Cause(s) of Impairment Addressed
CA404.0200R CALLEGUAS R1 CALLEGUAS CREEK REACH 1 (WAS MUGU LAGOON ON 1998 303(D) LIST) Data Unavailable 2002 Mercury

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TMDL Pollutant: Nickel

Total Waste Load Allocation:      Total Load Allocation:
Explicit Margin Of Safety:      Implicit Margin Of Safety: Not Reported
Units for Total Waste Load Allocation and Total Load Allocation:      TMDL Pollutant Source Type: Point/Nonpoint Source
TMDL End Point: (STAFF REPORT, PP. 37-43 AND BASIN PLAN AMENDMENT A RESOLUTION, PP. 2-4.) THE TMDLS ESTABLISH FOUR TYPES OF NUMERIC TARGETS: (1) CALIFORNIA TOXICS RULE (CTR) CRITERIA IN DISSOLVED FRACTION FOR COPPER, NICKEL, AND ZINC, AND IN TOTAL RECOVERABLE FORM FOR MERCURY AND SELENIUM; (2) FISH TISSUE TARGETS FOR MERCURY (BASED ON METHODOLOGY DEVELOPED BY THE US FISH AND WILDLIFE SERVICE (USFWS)); (3) BIRD EGG TARGETS FOR MERCURY AND SELENIUM; AND (4) SEDIMENT QUALITY GUIDELINES FOR COPPER, NICKEL, AND ZINC FOR 303(D) LISTED REACHES. THE ATTAINMENT OF SEDIMENT QUALITY TARGETS WILL BE EVALUATED IN COMBINATION WITH SEDIMENT TOXICITY DATA, IF AVAILABLE. WATER QUALITY THE CTR AQUATIC LIFE CRITERIA FOR WATER ARE SELECTED AS NUMERIC TARGETS FOR PROTECTION OF FRESHWATER AND MARINE LIFE FROM AQUATIC TOXICITY FOR DISSOLVED COPPER, NICKEL AND ZINC; AND FOR TOTAL MERCURY AND SELENIUM. SEPARATE TARGETS ARE ESTABLISHED FOR DRY-WEATHER AND WET-WEATHER CONDITIONS. THE 4-DAY AVERAGE CHRONIC CRITERION (CRITERION CONTINUOUS CONCENTRATION, OR CCC) AND 1-HOUR AVERAGE ACUTE CRITERION (CRITERION MAXIMUM CONCENTRATION, OR CMC) FOR EACH CONSTITUENT ARE INCLUDED AS TARGETS FOR THE TMDLS. CTR AQUATIC LIFE CRITERIA ARE NOT DEVELOPED FOR MERCURY, SO 30-DAY AVERAGE CTR HUMAN HEALTH CRITERIA (ORGANISMS ONLY) ARE APPLIED INSTEAD. THE CTR DEFINES NUMERIC CRITERIA FOR COPPER, NICKEL AND ZINC EXPRESSED AS DISSOLVED METAL CONCENTRATIONS, WHICH ARE HARDNESS-DEPENDENT. CTR ALSO PROVIDES METAL-SPECIFIC CONVERSION FACTORS FOR TRANSLATING DISSOLVED METAL VALUES INTO TOTAL METALS CONCENTRATIONS. THROUGH ITS USE OF THESE CONVERSION FACTORS, THE STATE DEMONSTRATES HOW TMDLS EXPRESSED IN TERMS OF TOTAL RECOVERABLE METALS WILL BE SUFFICIENT TO RESULT IN ATTAINMENT OF WATER QUALITY CRITERIA EXPRESSED IN TERMS OF DISSOLVED METALS. THE CTR CRITERIA FOR MERCURY AND SELENIUM ARE EXPRESSED IN TERMS OF TOTAL (UNFILTERED) MERCURY AND TOTAL (UNFILTERED) SELENIUM AND ARE NOT HARDNESS-DEPENDENT. THE MERCURY AND SELENIUM CRITERION WERE APPLIED DIRECTLY AS THE BASIS FOR THE MERCURY AND SELENIUM TMDLS. FISH TISSUE & BIRD EGG FISH TISSUE TARGETS ARE ESTABLISHED TO PROTECT HUMANS AND WILDLIFE FROM CONSUMPTION OF FISH AND OTHER AQUATIC ORGANISMS CONTAMINATED BY MERCURY. THE TMDLS INCLUDE A USEPA ADOPTED METHYLMERCURY TARGET (0.3 MG/KG) TO ACCOUNT FOR THE FACT THAT NEARLY 90-95% OF MERCURY ACCUMULATES IN FISH TISSUE IN THE FORM OF METHYLMERCURY; EPA DETERMINED IT IS MORE APPROPRIATE TO BASE THE METHYLMERCURY CRITERION ON A FISH TISSUE RESIDUE CONCENTRATION THAN ON AN AMBIENT WATER CONCENTRATION (STAFF REPORT, PP. 41). HOWEVER, BOTH FISH TISSUE AND WATER CRITERION ARE INCLUDED TO PROVIDE CONSERVATIVE MEASURES OF PROTECTION. IN ADDITION, THREE SIZES OF TROPHIC LEVEL-3 FISH TISSUE TARGETS ARE INCLUDED FOR PROTECTION OF WILDLIFE (BASED ON THE US FISH & WILDLIFE SERVICE METHODOLOGY THAT DEVELOPED NUMERIC TARGETS FOR THE SAN FRANCISCO BAY MERCURY TMDLS AND THE GUADALUPE RIVER WATERSHED MERCURY TMDLS); THESE TARGETS PROVIDE PROTECTION OF COASTAL OR SEMI-COASTAL HABITATS IN CALIFORNIA WITH SENSITIVE SPECIES. FINALLY, BIRD EGG TARGETS ARE APPROPRIATELY ESTABLISHED TO PROTECT SPECIES HIGHER UP ON THE FOOD WEB; SINCE MERCURY AND SELENIUM ARE KNOWN TO CAUSE REPRODUCTIVE FAILURE AND OTHER DEVELOPMENTAL EFFECTS, BIRD EGG CONCENTRATION TARGETS ARE ONE OF THE MOST DIRECT MEANS BY WHICH TO MEASURE IMPACTS. SEDIMENT ALTERNATIVE NUMERIC TARGETS FOR COPPER AND NICKEL IN SEDIMENT HAVE BEEN DESIGNATED AS TRIGGERS FOR SEDIMENT TOXICITY TESTING IN MUGU LAGOON. THE EFFECTS RANGE-LOW VALUES (ERLS, PUBLISHED BY THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION (NOAA)), COMBINED WITH EVIDENCE OF SEDIMENT TOXICITY DUE TO METALS, WERE CHOSEN AS THE SEDIMENT TARGETS AND ARE IN PLACE TO PROTECT BENTHIC ORGANISMS FROM SEDIMENT TOXICITY DUE TO METALS.

NPDES Allocation for Pollutant: Nickel
NPDES ID Other Non PCS Identification Waste Load Allocation Units
CA0053597

.26
LBS/DAY
CA0056294

.33
LBS/DAY


Listed Water Causes of Impairment for Nickel
Click on the underlined Waterbody ID for a Waterbody Report. Click on the underlined "Waterbody Map" literal for a map of the Assessment Unit.
Waterbody ID Waterbody Name Map Cycles Listed Cause(s) of Impairment Addressed
CA404.0200R CALLEGUAS R1 CALLEGUAS CREEK REACH 1 (WAS MUGU LAGOON ON 1998 303(D) LIST) Data Unavailable 2002 Nickel
CA404.0270R CONEJO CK R1 CONEJO CREEK REACH 1 (CONFL CALL TO SANTA ROSA RD) Data Unavailable 1996, 1998 Nickel
CA404.0340R CONEJO CK R2 CONEJO CREEK REACH 2 (SANTA ROSA RD TO THO. OAKS CITY LIMIT) Data Unavailable 1998 Nickel
CA404.0400R CONEJO CK R3 CONEJO CREEK REACH 3 (THOUSAND OAKS CITY LIMIT TO LYNN RD.) Data Unavailable 1998 Nickel

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TMDL Pollutant: Selenium

Total Waste Load Allocation:      Total Load Allocation:
Explicit Margin Of Safety:      Implicit Margin Of Safety: Not Reported
Units for Total Waste Load Allocation and Total Load Allocation:      TMDL Pollutant Source Type: Point/Nonpoint Source
TMDL End Point: STAFF REPORT, PP. 37-43 AND BASIN PLAN AMENDMENT A RESOLUTION, PP. 2-4.) THE TMDLS ESTABLISH FOUR TYPES OF NUMERIC TARGETS: (1) CALIFORNIA TOXICS RULE (CTR) CRITERIA IN DISSOLVED FRACTION FOR COPPER, NICKEL, AND ZINC, AND IN TOTAL RECOVERABLE FORM FOR MERCURY AND SELENIUM; (2) FISH TISSUE TARGETS FOR MERCURY (BASED ON METHODOLOGY DEVELOPED BY THE US FISH AND WILDLIFE SERVICE (USFWS)); (3) BIRD EGG TARGETS FOR MERCURY AND SELENIUM; AND (4) SEDIMENT QUALITY GUIDELINES FOR COPPER, NICKEL, AND ZINC FOR 303(D) LISTED REACHES. THE ATTAINMENT OF SEDIMENT QUALITY TARGETS WILL BE EVALUATED IN COMBINATION WITH SEDIMENT TOXICITY DATA, IF AVAILABLE. WATER QUALITY THE CTR AQUATIC LIFE CRITERIA FOR WATER ARE SELECTED AS NUMERIC TARGETS FOR PROTECTION OF FRESHWATER AND MARINE LIFE FROM AQUATIC TOXICITY FOR DISSOLVED COPPER, NICKEL AND ZINC; AND FOR TOTAL MERCURY AND SELENIUM. SEPARATE TARGETS ARE ESTABLISHED FOR DRY-WEATHER AND WET-WEATHER CONDITIONS. THE 4-DAY AVERAGE CHRONIC CRITERION (CRITERION CONTINUOUS CONCENTRATION, OR CCC) AND 1-HOUR AVERAGE ACUTE CRITERION (CRITERION MAXIMUM CONCENTRATION, OR CMC) FOR EACH CONSTITUENT ARE INCLUDED AS TARGETS FOR THE TMDLS. CTR AQUATIC LIFE CRITERIA ARE NOT DEVELOPED FOR MERCURY, SO 30-DAY AVERAGE CTR HUMAN HEALTH CRITERIA (ORGANISMS ONLY) ARE APPLIED INSTEAD. THE CTR DEFINES NUMERIC CRITERIA FOR COPPER, NICKEL AND ZINC EXPRESSED AS DISSOLVED METAL CONCENTRATIONS, WHICH ARE HARDNESS-DEPENDENT. CTR ALSO PROVIDES METAL-SPECIFIC CONVERSION FACTORS FOR TRANSLATING DISSOLVED METAL VALUES INTO TOTAL METALS CONCENTRATIONS. THROUGH ITS USE OF THESE CONVERSION FACTORS, THE STATE DEMONSTRATES HOW TMDLS EXPRESSED IN TERMS OF TOTAL RECOVERABLE METALS WILL BE SUFFICIENT TO RESULT IN ATTAINMENT OF WATER QUALITY CRITERIA EXPRESSED IN TERMS OF DISSOLVED METALS. THE CTR CRITERIA FOR MERCURY AND SELENIUM ARE EXPRESSED IN TERMS OF TOTAL (UNFILTERED) MERCURY AND TOTAL (UNFILTERED) SELENIUM AND ARE NOT HARDNESS-DEPENDENT. THE MERCURY AND SELENIUM CRITERION WERE APPLIED DIRECTLY AS THE BASIS FOR THE MERCURY AND SELENIUM TMDLS. FISH TISSUE & BIRD EGG FISH TISSUE TARGETS ARE ESTABLISHED TO PROTECT HUMANS AND WILDLIFE FROM CONSUMPTION OF FISH AND OTHER AQUATIC ORGANISMS CONTAMINATED BY MERCURY. THE TMDLS INCLUDE A USEPA ADOPTED METHYLMERCURY TARGET (0.3 MG/KG) TO ACCOUNT FOR THE FACT THAT NEARLY 90-95% OF MERCURY ACCUMULATES IN FISH TISSUE IN THE FORM OF METHYLMERCURY; EPA DETERMINED IT IS MORE APPROPRIATE TO BASE THE METHYLMERCURY CRITERION ON A FISH TISSUE RESIDUE CONCENTRATION THAN ON AN AMBIENT WATER CONCENTRATION (STAFF REPORT, PP. 41). HOWEVER, BOTH FISH TISSUE AND WATER CRITERION ARE INCLUDED TO PROVIDE CONSERVATIVE MEASURES OF PROTECTION. IN ADDITION, THREE SIZES OF TROPHIC LEVEL-3 FISH TISSUE TARGETS ARE INCLUDED FOR PROTECTION OF WILDLIFE (BASED ON THE US FISH & WILDLIFE SERVICE METHODOLOGY THAT DEVELOPED NUMERIC TARGETS FOR THE SAN FRANCISCO BAY MERCURY TMDLS AND THE GUADALUPE RIVER WATERSHED MERCURY TMDLS); THESE TARGETS PROVIDE PROTECTION OF COASTAL OR SEMI-COASTAL HABITATS IN CALIFORNIA WITH SENSITIVE SPECIES. FINALLY, BIRD EGG TARGETS ARE APPROPRIATELY ESTABLISHED TO PROTECT SPECIES HIGHER UP ON THE FOOD WEB; SINCE MERCURY AND SELENIUM ARE KNOWN TO CAUSE REPRODUCTIVE FAILURE AND OTHER DEVELOPMENTAL EFFECTS, BIRD EGG CONCENTRATION TARGETS ARE ONE OF THE MOST DIRECT MEANS BY WHICH TO MEASURE IMPACTS. SEDIMENT ALTERNATIVE NUMERIC TARGETS FOR COPPER AND NICKEL IN SEDIMENT HAVE BEEN DESIGNATED AS TRIGGERS FOR SEDIMENT TOXICITY TESTING IN MUGU LAGOON. THE EFFECTS RANGE-LOW VALUES (ERLS, PUBLISHED BY THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION (NOAA)), COMBINED WITH EVIDENCE OF SEDIMENT TOXICITY DUE TO METALS, WERE CHOSEN AS THE SEDIMENT TARGETS AND ARE IN PLACE TO PROTECT BENTHIC ORGANISMS FROM SEDIMENT TOXICITY DUE TO METALS.

NPDES Allocation for Pollutant: Selenium
NPDES ID Other Non PCS Identification Waste Load Allocation Units
CA0056294



CA0055221



CA0059501



CA0063274



CA0053597




Listed Water Causes of Impairment for Selenium
Click on the underlined Waterbody ID for a Waterbody Report. Click on the underlined "Waterbody Map" literal for a map of the Assessment Unit.
Waterbody ID Waterbody Name Map Cycles Listed Cause(s) of Impairment Addressed
CA404.0260R CALLEGUAS R4 CALLEGUAS CREEK REACH 4 (WAS REVOLON SLOUGH MAIN BRANCH: MUGU LAGOON TO CENTRAL AVENUE ON 1998 303D LIST) Data Unavailable 2002 Selenium
CA404.0710R ARRYO SIMI R1 ARROYO SIMI REACH 1 (MOORPARK FRWY (23) TO BREA CYN) Data Unavailable 1996, 1998 Selenium

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TMDL Pollutant: Zinc

Total Waste Load Allocation:      Total Load Allocation:
Explicit Margin Of Safety:      Implicit Margin Of Safety: Not Reported
Units for Total Waste Load Allocation and Total Load Allocation:      TMDL Pollutant Source Type: Nonpoint Source
TMDL End Point: STAFF REPORT, PP. 37-43 AND BASIN PLAN AMENDMENT A RESOLUTION, PP. 2-4.) THE TMDLS ESTABLISH FOUR TYPES OF NUMERIC TARGETS: (1) CALIFORNIA TOXICS RULE (CTR) CRITERIA IN DISSOLVED FRACTION FOR COPPER, NICKEL, AND ZINC, AND IN TOTAL RECOVERABLE FORM FOR MERCURY AND SELENIUM; (2) FISH TISSUE TARGETS FOR MERCURY (BASED ON METHODOLOGY DEVELOPED BY THE US FISH AND WILDLIFE SERVICE (USFWS)); (3) BIRD EGG TARGETS FOR MERCURY AND SELENIUM; AND (4) SEDIMENT QUALITY GUIDELINES FOR COPPER, NICKEL, AND ZINC FOR 303(D) LISTED REACHES. THE ATTAINMENT OF SEDIMENT QUALITY TARGETS WILL BE EVALUATED IN COMBINATION WITH SEDIMENT TOXICITY DATA, IF AVAILABLE. WATER QUALITY THE CTR AQUATIC LIFE CRITERIA FOR WATER ARE SELECTED AS NUMERIC TARGETS FOR PROTECTION OF FRESHWATER AND MARINE LIFE FROM AQUATIC TOXICITY FOR DISSOLVED COPPER, NICKEL AND ZINC; AND FOR TOTAL MERCURY AND SELENIUM. SEPARATE TARGETS ARE ESTABLISHED FOR DRY-WEATHER AND WET-WEATHER CONDITIONS. THE 4-DAY AVERAGE CHRONIC CRITERION (CRITERION CONTINUOUS CONCENTRATION, OR CCC) AND 1-HOUR AVERAGE ACUTE CRITERION (CRITERION MAXIMUM CONCENTRATION, OR CMC) FOR EACH CONSTITUENT ARE INCLUDED AS TARGETS FOR THE TMDLS. CTR AQUATIC LIFE CRITERIA ARE NOT DEVELOPED FOR MERCURY, SO 30-DAY AVERAGE CTR HUMAN HEALTH CRITERIA (ORGANISMS ONLY) ARE APPLIED INSTEAD. THE CTR DEFINES NUMERIC CRITERIA FOR COPPER, NICKEL AND ZINC EXPRESSED AS DISSOLVED METAL CONCENTRATIONS, WHICH ARE HARDNESS-DEPENDENT. CTR ALSO PROVIDES METAL-SPECIFIC CONVERSION FACTORS FOR TRANSLATING DISSOLVED METAL VALUES INTO TOTAL METALS CONCENTRATIONS. THROUGH ITS USE OF THESE CONVERSION FACTORS, THE STATE DEMONSTRATES HOW TMDLS EXPRESSED IN TERMS OF TOTAL RECOVERABLE METALS WILL BE SUFFICIENT TO RESULT IN ATTAINMENT OF WATER QUALITY CRITERIA EXPRESSED IN TERMS OF DISSOLVED METALS. THE CTR CRITERIA FOR MERCURY AND SELENIUM ARE EXPRESSED IN TERMS OF TOTAL (UNFILTERED) MERCURY AND TOTAL (UNFILTERED) SELENIUM AND ARE NOT HARDNESS-DEPENDENT. THE MERCURY AND SELENIUM CRITERION WERE APPLIED DIRECTLY AS THE BASIS FOR THE MERCURY AND SELENIUM TMDLS. FISH TISSUE & BIRD EGG FISH TISSUE TARGETS ARE ESTABLISHED TO PROTECT HUMANS AND WILDLIFE FROM CONSUMPTION OF FISH AND OTHER AQUATIC ORGANISMS CONTAMINATED BY MERCURY. THE TMDLS INCLUDE A USEPA ADOPTED METHYLMERCURY TARGET (0.3 MG/KG) TO ACCOUNT FOR THE FACT THAT NEARLY 90-95% OF MERCURY ACCUMULATES IN FISH TISSUE IN THE FORM OF METHYLMERCURY; EPA DETERMINED IT IS MORE APPROPRIATE TO BASE THE METHYLMERCURY CRITERION ON A FISH TISSUE RESIDUE CONCENTRATION THAN ON AN AMBIENT WATER CONCENTRATION (STAFF REPORT, PP. 41). HOWEVER, BOTH FISH TISSUE AND WATER CRITERION ARE INCLUDED TO PROVIDE CONSERVATIVE MEASURES OF PROTECTION. IN ADDITION, THREE SIZES OF TROPHIC LEVEL-3 FISH TISSUE TARGETS ARE INCLUDED FOR PROTECTION OF WILDLIFE (BASED ON THE US FISH & WILDLIFE SERVICE METHODOLOGY THAT DEVELOPED NUMERIC TARGETS FOR THE SAN FRANCISCO BAY MERCURY TMDLS AND THE GUADALUPE RIVER WATERSHED MERCURY TMDLS); THESE TARGETS PROVIDE PROTECTION OF COASTAL OR SEMI-COASTAL HABITATS IN CALIFORNIA WITH SENSITIVE SPECIES. FINALLY, BIRD EGG TARGETS ARE APPROPRIATELY ESTABLISHED TO PROTECT SPECIES HIGHER UP ON THE FOOD WEB; SINCE MERCURY AND SELENIUM ARE KNOWN TO CAUSE REPRODUCTIVE FAILURE AND OTHER DEVELOPMENTAL EFFECTS, BIRD EGG CONCENTRATION TARGETS ARE ONE OF THE MOST DIRECT MEANS BY WHICH TO MEASURE IMPACTS. SEDIMENT ALTERNATIVE NUMERIC TARGETS FOR COPPER AND NICKEL IN SEDIMENT HAVE BEEN DESIGNATED AS TRIGGERS FOR SEDIMENT TOXICITY TESTING IN MUGU LAGOON. THE EFFECTS RANGE-LOW VALUES (ERLS, PUBLISHED BY THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION (NOAA)), COMBINED WITH EVIDENCE OF SEDIMENT TOXICITY DUE TO METALS, WERE CHOSEN AS THE SEDIMENT TARGETS AND ARE IN PLACE TO PROTECT BENTHIC ORGANISMS FROM SEDIMENT TOXICITY DUE TO METALS.


Listed Water Causes of Impairment for Zinc
Click on the underlined Waterbody ID for a Waterbody Report. Click on the underlined "Waterbody Map" literal for a map of the Assessment Unit.
Waterbody ID Waterbody Name Map Cycles Listed Cause(s) of Impairment Addressed
CA404.0200R CALLEGUAS R1 CALLEGUAS CREEK REACH 1 (WAS MUGU LAGOON ON 1998 303(D) LIST) Data Unavailable 2002 Zinc
CA404.0710R ARRYO SIMI R1 ARROYO SIMI REACH 1 (MOORPARK FRWY (23) TO BREA CYN) Data Unavailable 1996, 1998 Zinc

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