AIPG-TX

The aquatic life and human health surface water RBEL (risk-based exposure limit) tables have been updated and are available on the TCEQ website. These tables can be found as the second category under the TRRP PCLs at the following link: https://www.tceq.texas.gov/remediation/trrp/trrppcls.html

They are also available as companion documents to, “Determining PCLs for Surface Water and Sediment (TRRP-24)” which is available with the TRRP guidance documents at: https://www.tceq.texas.gov/remediation/trrp/guidance.html

The following changes were made to the aquatic life table

• The freshwater acute and chronic RBEL values for ammonia (as total ammonia nitrogen) were corrected. The 2014 table revision had a units error. The correct RBELs should be 1,700 ug/L (acute) and 410 ug/L (chronic) rather than 1.7 ug/L (acute) and 0.41 ug/L (chronic).

The following changes were made to the human health table

• Values for the following chemicals were revised based on the June 2015 revisions to the Federal Recommended Water Quality Criteria: acenaphthene; acrolein; anthracene; benzo(b)fluoranthene; benzo(k)fluoranthene; bis(2-chloro-1-methylethyl) ether; butylbenzyl phthalate; 2-chloronaphthalene; 2-chlorophenol; cyanide; 2,4-D; dibenzo(a,h)anthracene; 1,4-dichlorobenzene; 1,4-dichorophenol; 1,2-diphenylhydrazine; 1,2-(Trans) dichloroethylene; diethyl phthalate; dimethyl phthalate; dinitrophenols; 2,4-dinitrophenol; 2,4-dinitrotoluene; 1,2-diphenylhydrazine; endosulfan (alpha); endosulfan (beta); endosulfan sulfate; endrin aldehyde; fluoranthene; fluorene; hexachlorocyclohexane (technical); hexachlorocyclopentadiene; indeno (1,2,3-cd) pyrene; isophorone; methyl bromide; 3-methyl-4-chlorophenol (addition to list); 2-methyl-4,6-dinitrophenol; phenol; pyrene; toluene; 1,2,4-trichlorobenzene; and 2,4,6-trichlorophenol.
• More information about the federal human health criteria changes is available at: http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhfinal.cfm
• Although the federal criteria changed, for some chemicals there was no change to the RBEL table because a state water quality standard exists.

The aquatic life and surface water RBEL tables will be updated periodically to reflect new state or federal criteria, changes to ecological screening benchmarks, and/or other information (e.g., toxicological data, persistence information). These revised tables should be used for TRRP submittals that involve releases to surface water. For additional information on the surface water RBEL tables, contact Vickie Reat at vickie.reat@tceq.texas.gov.

Henry M. Wise, P.G.
The Wise Report