Ambient Water Quality Guidelines for Chlorophenols

Water Quality

Ambient Water Quality Guidelines for Chlorophenols

RECREATION

General

There are no data documenting the effects of chlorophenols on recreational uses of water. Human taste and odor thresholds for some chlorophenols in water are available, as are taste thresholds for some chlorophenols in fish meat. No published taste thresholds for crustacean or mollusc meat were found for the chlorophenols.

Primary-Contact Recreation

Swimming involves contact of the face with the water; taste and odor thresholds for the chlorophenols should be met in water used for swimming. These thresholds are the critical factors determining drinking water aesthetic guidelines, and should give adequate protection to waters used for swimming.

Water used for Primary-Contact Recreation should meet the Drinking Water Aesthetic Guidelines.

Secondary-Contact Recreation

The critical activity which occurs in secondary-contact recreational waters is the harvest of fish, molluscs, and crustaceans for human consumption. If chlorophenols are present in appreciable quantities in the water, they bioconcentrate in the flesh of organisms and impart an objectionable taste to the meat. One needs to back-calculate from known taste thresholds in the meat, available only for fish, and not for molluscs or crustaceans, and, using the experimental or calculated bioconcentration factors for edible tissues, determine water levels for chlorophenols which would prevent taste problems in the fish. If one does this calculation, using a safety factor of 10 to allow for people with greater taste sensitivity than those on the original taste panel, the numbers generated are generally higher than the guidelines for the protection of the growth and reproduction of the organism. Thus, the aquatic life guidelines would take precedence and give adequate protection against taste problems in the edible tissues. Use of the aquatic life guidelines may result in some marginal taste problems with filter feeders and bottom feeding fish, and with 2,4-dichlorophenol.

Water used for Secondary-Contact Recreation should meet the Aquatic Life Toxicity Guidelines, if fishing or harvesting of crustaceans or molluscs occurs; otherwise it should meet the Aesthetics Guidelines below.

Aesthetics

For distant scenic and vista uses, no guidelines are necessary; for proximal uses the odor thresholds in water are appropriate. These vary with water temperature and are a function of the molecular weight and volatility of the chlorophenol. The more chlorine substituents present, the lower the volatility and higher the threshold concentration for odor detection.

Water designated for Aesthetic use should not exceed the following.

0.3 µg/L MCPs or DCPs
11 µg/L TCPs
600 µg/L TTCP
860 µg/L PCP


	Water Quality Ambient Water Quality Guidelines for Chlorophenols RECREATION *General* There are no data documenting the effects of chlorophenols on recreational uses of water. Human taste and odor thresholds for some chlorophenols in water are available, as are taste thresholds for some chlorophenols in fish meat. No published taste thresholds for crustacean or mollusc meat were found for the chlorophenols. Primary-Contact Recreation Swimming involves contact of the face with the water; taste and odor thresholds for the chlorophenols should be met in water used for swimming. These thresholds are the critical factors determining drinking water aesthetic guidelines, and should give adequate protection to waters used for swimming. Water used for Primary-Contact Recreation should meet the Drinking Water Aesthetic Guidelines. Secondary-Contact Recreation The critical activity which occurs in secondary-contact recreational waters is the harvest of fish, molluscs, and crustaceans for human consumption. If chlorophenols are present in appreciable quantities in the water, they bioconcentrate in the flesh of organisms and impart an objectionable taste to the meat. One needs to back-calculate from known taste thresholds in the meat, available only for fish, and not for molluscs or crustaceans, and, using the experimental or calculated bioconcentration factors for edible tissues, determine water levels for chlorophenols which would prevent taste problems in the fish. If one does this calculation, using a safety factor of 10 to allow for people with greater taste sensitivity than those on the original taste panel, the numbers generated are generally higher than the guidelines for the protection of the growth and reproduction of the organism. Thus, the aquatic life guidelines would take precedence and give adequate protection against taste problems in the edible tissues. Use of the aquatic life guidelines may result in some marginal taste problems with filter feeders and bottom feeding fish, and with 2,4-dichlorophenol. Water used for Secondary-Contact Recreation should meet the Aquatic Life Toxicity Guidelines, if fishing or harvesting of crustaceans or molluscs occurs; otherwise it should meet the Aesthetics Guidelines below. *Aesthetics* For distant scenic and vista uses, no guidelines are necessary; for proximal uses the odor thresholds in water are appropriate. These vary with water temperature and are a function of the molecular weight and volatility of the chlorophenol. The more chlorine substituents present, the lower the volatility and higher the threshold concentration for odor detection. Water designated for Aesthetic use should not exceed the following. 0.3 µg/L MCPs or DCPs 11 µg/L TCPs 600 µg/L TTCP 860 µg/L PCP