La. Admin. Code tit. 33 § IX-1121

Current through Register Vol. 50, No. 6, June 20, 2024

Section IX-1121 - Regulation of Toxic Substances Based on the General Criteria

A. Introduction

1. The water quality standards in this Chapter provide for the protection of human, plant, and animal life from the deleterious effects of toxic substances. The general criteria (LAC 33:IX.1113.B.5), in particular, require that state waters be free from the effects of toxic substances. This requirement is especially applicable to those toxic substances for which no numeric criteria are established.

2. The following methods are developed to protect state waters from the effects of toxic substances as required under the general criteria and where no numeric criteria exist. The methods follow the permitting policies of the department. The resulting permit (effluent) limitations imposed on discharges prevent toxic in-stream conditions as required under the general criteria.

B. Effluent Characterization/Toxicity Testing and/or Instream Assessment

1. When determining the need for limits based on water quality, the Office of Environmental Services may identify data needs and request that the permittee submit additional data along with the application. Permits may be placed into three categories:

a. discharges for which adequate data exist;

b. discharges for which some data exist; and

c. discharges for which no water-quality-related data are available.

2. In areas of known ambient toxicity, both specific chemical data and available whole effluent toxicity data representative of the facility's discharge into the receiving water will be reviewed.

3. In general, whole effluent toxicity testing will be required in the permit for discharges where data are insufficient to demonstrate that any discharge does not or will not contribute to ambient toxicity.

a. Tests will be routinely run for the life of the permit on an established schedule dependent upon on the variability of the discharge and on whether effluent toxicity is suspected or unknown.

b. Both acute toxicity and chronic toxicity tests may be required. Test methods found in the following sources or their updated versions should be followed: "Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms," 4th Edition, EPA/600/4-90/027F, EPA, 1993; "Short-Term Methods for Estimating the Chronic Toxicity of Effluents And Receiving Waters To Freshwater Organisms," 3rd Edition, EPA/600/4-91/002, EPA, 1994; and "Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms," 2nd Edition, EPA/600/4-91/003, EPA.

i. Acute toxicity tests will be considered for "end-of-pipe" effluent. Dilution water will be receiving water collected at a point upstream of or adequately removed from the discharge point(s).

ii. For chronic toxicity tests of effluent, dilution water will also be receiving stream water collected at a point upstream of or adequately removed from the discharge point(s). In flowing water bodies, one dilution in the series required to calculate the no-observed-effect level (NOEL) will reflect the 7Q10 flow dilution. In some water bodies the 7Q10 flow may not be considered adequate, and a more appropriate low flow will be used for dilution calculations.

iii. Multiple toxicity tests using more than one species of test organisms will normally be required. The following tests and species are considered applicable to and representative of Louisiana waters. Other applicable tests and test species may also be used after approval by the department. In general, some combination of the following tests and species will be required:

(a). for receiving water bodies with salinities less than 2 0 (2 ppt or 2,000 ppm):

(i). 48-hour Ceriodaphnia or Daphnia pulex acute survival;

(ii). 48- and 96-hour fathead minnow (Pimephales promelas) static renewal acute survival;

(iii). 7-day Ceriodaphnia chronic reproduction and survival;

(iv). 7-day fathead minnow chronic survival and teratogenicity;

(v). 7-day fathead minnow chronic growth and survival; and

(vi). 4-day Selenastrum chronic growth test;

(b). for receiving water bodies with salinities equal to or greater than 2 0 (2 ppt or 2,000 ppm):

(i). 48-hour mysid shrimp acute survival;

(ii). 48- and 96-hour sheepshead minnow (Cyprinodon variegatus) static renewal acute survival;

(iii). 48-hour inland silverside (Menidia beryllina) static renewal acute survival;

(iv). 7-day mysid shrimp survival, growth, and fecundity;

(v). 7-day sheepshead minnow larval survival and growth; and

(vi). 7-day inland silverside larval survival and growth; and

(c). i f a control test reveals upstream ambient water to be toxic, the discharger will redo the toxicity tests using EPA- and department-approved reconstituted water with hardness, alkalinity, pH, and conductivity comparable to the ambient stream for dilution. The department will evaluate the toxicity data if upstream toxicity is indicated.

4. For water bodies whose designated use is as a drinking water supply, the department will calculate the in-stream concentration for all discharged pollutants for which EPA has promulgated a maximum contaminant level (MCL). The permittee will be required to submit to the Office of Environmental Services sufficient effluent characterization data to make these calculations. Where dilution calculations indicate that in-stream concentrations may exceed the MCL requirements at appropriate flow conditions, the permittee may be required to conduct in-stream chemical monitoring or monitoring at the water supply.

5. To protect human health by eliminating chronic exposure to potentially toxic amounts of pollutants from aquatic species consumed by humans, the department will calculate the in-stream concentrations of all applicable pollutants for which EPA has published human health criteria in the Quality Criteria for Water, 1986, EPA 440/5-86-001, or subsequent revisions. The permittee will be required to submit to the Office of Environmental Services sufficient effluent characterization data to make these calculations. For operational considerations, if dilution calculations show that after mixing, a suspected carcinogen would be present in the receiving water body at a concentration associated with a 10^-6 risk level, in-stream chemical monitoring may be required of the appropriate dischargers. The department will list the water body as a priority water body and develop a wasteload allocation or make other consideration for it.

C. Options for Implementing Whole Effluent Toxicity Permit Requirements. The option or combination of options to be selected by the department from the following will depend on data availability at the time of permit application and on whether toxicity is known or suspected.

1. Option 1. Final whole effluent toxicity limits are included in the permit with an interim schedule for conducting toxicity reduction that begins upon issuance of the permit.

2. Option 2. The permittee will conduct whole effluent toxicity testing with pass/fail criteria that will trigger toxicity reduction efforts. A clause requiring this will be placed in the permit to take effect if the pass/fail criteria are exceeded when any toxic impact exhibited shows a statistically significant difference between the effluent sample and the control. If any toxicity test is failed, an opportunity for retesting will be given. When no toxicity is demonstrated or no toxicity criteria are exceeded, testing may be reduced for the remainder of the term of the permit. If any subsequent testing indicates toxicity, the permittee must revert to the more frequent monitoring schedule.

3. Option 3. No whole effluent toxicity limits are included in the permit. Limits based on MCLs and/or on protecting human health are included, or a schedule for their inclusion is incorporated into the permit.

4. Option 4. No whole effluent toxicity limits are included in the permit.

5. Option 5. A combination of the above four options may be applied.

D. References. The following references were used in developing or were cited in this Section.

1. U.S. Environmental Protection Agency. 1986. Quality Criteria for Water: 1986. EPA 440/5-86-001. Washington, D.C.: U.S. Government Printing Office.

2. U.S. Environmental Protection Agency. 1991. Methods for Aquatic Toxicity Identification Evaluations: Phase I, Toxicity Characterization Procedures. EPA/600/6-91/003. Washington, D.C.: EPA.

3. U.S. Environmental Protection Agency. 1991. Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms. 2nd Edition. EPA/600/4-91/003.

4. U.S. Environmental Protection Agency. 1991. Technical Support Document for Water Quality-Based Toxics Control. EPA/505/2-90-001.

5. U.S. Environmental Protection Agency. 1993. Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms. 4th Edition. EPA/600/4-90/027F.

6. U.S. Environmental Protection Agency. 1994. Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. 3rd Edition. EPA/600/4-91/002.

E. Additional Toxicity Testing Guidance. The following references are cited as guidance documents that are used for biomonitoring:

1. U.S. Environmental Protection Agency. 1994. Methods for Measuring the Toxicity and Bioaccumulation of Sediment-Associated Contaminants with Freshwater Invertebrates. EPA/600/R-94/024.

2. U.S. Environmental Protection Agency. 1994. Methods for Assessing the Toxicity of Sediment Associated Contaminants with Estuarine and Marine Amphipods. EPA/600/R-94/025.

La. Admin. Code tit. 33, § IX-1121

Promulgated by the Department of Environmental Quality, Office of Water Resources, LR 15:738 (September 1989), amended LR 17:264 (March 1991), LR 20:883 (August 1994), amended by the Office of Environmental Assessment, Environmental Planning Division, LR 25:2404 (December 1999), LR 26:2548 (November 2000), amended by the Office of the Secretary, Legal Affairs Division, LR 31:2507 (October 2005), LR 33:832 (May 2007), LR 33:2163 (October 2007), Amended by the Office of the Secretary, Legal Affairs and Criminal Investigations Division, LR 461555 (11/1/2020).

AUTHORITY NOTE: Promulgated in accordance with R.S. 30:2074(B)(1).