A Tool for Industrial Water Conservation: Mass-based Pretreatment Permits

In recent years, industrial users connected to municipal sewerage systems have been encouraged to utilize pollution prevention techniques to reduce their water usage, as well as the pollutants being discharged to a receiving wastewater treatment plant. This is seen as a necessary part of any industrial environmental program where pollutants can be reduced at the source in addition to pretreatment of the discharge. Among the techniques used in pollution prevention have been the development and use of solvent management plans, raw material substitutions, and water recycling and conservation.

With a particular emphasis on water conservation, some industrial users who attempt to aggressively reduce the amount of water they discharge can encounter a problem with meeting discharge limitations specified in their Industrial Pretreatment Permit. As they reduce the volume of their wastewater, without an accompanying reduction in the mass of pollutants in the discharge, water conservation efforts can result in a higher concentration of discharged pollutants. Higher pollutant concentrations can lead to potential permit violations and possible enforcement issues that would have to be addressed by the permitting authority.

However, if the specific environmental regulation which establishes discharge limits for particular industrial pretreatment categories supports their use, there can be a solution to this dilemma: mass based discharge limits. In many cases the use of permits requiring mass based limits only can address the problem described above and will serve to encourage further water conservation efforts by industry.

According to Jeffrey Larson, Manager of the Permitting, Compliance, and Enforcement Program within the Georgia Environmental Protection Division’s (EPD’s) Water Protection Branch, “mass based limits are a real possibility for industrial pretreatment permits provided that Federal categorical pretreatment regulations do not specifically establish concentration based numbers for a particular industrial type. It’s important that an industry check with the industrial pretreatment permitting authority prior to implementing water conservation methods if that industry is concerned that they may encounter problems meeting their permit limits due to a proposal to reduce water use. The permitting authority can then re-check the existing permit limits to see if a proposed water conservation proposal will have an impact. Where a problem arises, the permitting authority can then evaluate whether there are any options available to the industry whereby mass based limits can be used.” Larson goes on to say “that EPD wants to encourage water conservation and will assist an industry, within the confines of the applicable regulation, to determine if mass based limits can be successfully used in a permit.”

Mass based limits have been effectively employed in the administration of the local industrial pretreatment program by Dalton Utilities in Dalton, GA. There are a significant number of textile mills on Dalton Utilities’ sewerage system. Although textile mills which discharge directly to surface waters are regulated under Federal Effluent Limitation Guidelines, the Federal Categorical Pretreatment Standards for various subcategories of textile operations only require compliance with the General Pretreatment Regulations and do not establish specific nationwide numerical discharge limits for textile mills. This provided Dalton Utilities with an option and opportunity to use mass based limits as the permit control for its textile mills for pollutants of concern (Biological Oxygen Demand, Chemical Oxygen Demand, etc.). This also provides support and to the mills to continue their efforts to reduce water usage.

By using the permitting flexibility that may be available to the industrial pretreatment permitting authority, pretreaters, such as those in Dalton, can continue with their efforts in water conservation and successfully fulfill the intent of pollution prevention–truly a win-win situation.

–Jeff Larson, EPD and Eileen Miles, P²AD