EPA has published a plan and schedule to consider developing and revising effluent guidelines, including those for drinking water supply and treatment. The plan for 2004/2005 itself does not establish any new requirements – it simply announces EPA's decision to proceed with rulemakings which may lead to new requirements for facilities in four industries.
EPA publishes an Effluent Guidelines Plan every other year. The Plan is required by Section 304(m) of the Clean Water Act. EPA published the preliminary plan for public comment on December 31, 2003. EPA did not identify the Drinking Water Supply and Treatment industrial sector (SIC Code 4941) as a potential candidate for effluent guidelines development in the preliminary Plan.
At that time, EPA concluded that almost all of the hazard posed by the sector was due to a few facilities. In particular, EPA's analysis showed that a single facility was contributing over 96% of the toxic-weighted pollutant discharges included in the agency's Permit Compliance System (PCS) for the entire sector.
Public comments on the preliminary plan suggested that EPA consider developing effluent guidelines for the sector because of the potential of drinking water supply and treatment plants to discharge non-trivial amounts of non-conventional and toxic pollutants (e.g., metals and salts).
In particular, commenters stated that many drinking water facilities have the potential to discharge significant quantities of conventional and toxic pollutants, and noted that the source of these pollutants can include drinking water treatment sludges and reverse osmosis reject wastewaters. Consequently, EPA attempted to collect additional information and re-evaluated the information in the docket supporting its final 2004 Plan.
Based on information in the 1997 Economic Census, EPA estimates there are 3,700 drinking water treatment and supply facilities in the United States that are large enough to qualify for this program. EPA's primary source of wastewater data for this industry is its Permit Compliance System (PCS). This database contains information required by the NPDES Permit Program for major dischargers across the country.
A major discharger is any NPDES facility or activity classified as such by the Regional Administrator, or, in the case of approved State Programs, the Regional Administrator in conjunction with the State Director. Major industrial facilities are determined based on specific ratings criteria developed by EPA and approved State Programs.
EPA does not require states to include data for other dischargers (e.g., minor and indirect dischargers) in PCS, so little information is available about industries like this one that are dominated by minor and indirect dischargers. PCS lists approximately 900 drinking water supply and treatment facilities as having minor permits for the year 2000, but includes only limited data on discharge flow or pollutant concentrations for these dischargers. Consequently, EPA was unable to quantify discharges from these facilities. PCS also contained information on 16 drinking water supply and treatment facilities with major permits for the year 2000 which EPA was able to analyze.
EPA found that the toxic-weighted pollutant discharges for these 16 facilities ranged from significant to very low, with the majority attributable to the discharges from three facilities. Total residual chlorine and metals (e.g., iron, manganese, and aluminum) represent most of the TWPE discharges from these three facilities. For the remaining 13 facilities, PCS data indicate that pollutants are being discharged at or near the detection levels, raising questions about further treatability of these pollutants using end-of-pipe treatment.
More recent PCS information suggests the TWPE discharges at some of these 16 facilities have decreased. In particular, two of the three facilities with top hazard scores for the year 2000 had significant reductions in their pollutant discharges within the last four years. One facility discontinued its wastewater discharges and the other facility recently added technology to properly dewater its wastewater treatment sludges which resulted in pollutant reductions of 85% or more.
While this PCS data suggest that many drinking water supply and treatment facilities with direct discharging permits are not discharging pollutants in significant concentrations, it also supports commenters' statements that some drinking water treatment and supply facilities may be discharging non-trivial amounts of toxic and non- conventional pollutants.
Because EPA only has discharge data on a limited number of facilities in this category, and this data shows at least one facility with potentially non-trivial discharges, EPA cannot rule out the possibility that a significant number of the facilities in this category have non-trivial discharges. Therefore, EPA has decided to identify the drinking water supply and treatment industry sector in its final 2004 pan and to complete an effluent guidelines rulemaking for this industry within three years.
The final 2004 plan identifies three other industries to consider for effluent guidelines development or revision. Two industrial sectors are identified for potential revisions to existing effluent guidelines: Vinyl Chloride Manufacturing and Chlor-Alkali manufacturing. A third, unregulated industrial category, covers Airport Deicing Operations.
For additional information concerning this action, you can contact Carey A. Johnston at (202) 566-1014 at the U.S. Environmental Protection Agency, Office of Water, Engineering and Analysis Division (4303T), 1200 Pennsylvania Avenue, NW, Washington, D.C., or send an e-mail to [email protected].
