Pretreatment
WHAT IS PRETREATMENT?
Pretreatment refers to the removal of industrial contaminants from wastewater prior to the release of the wastewater into public sewer lines. This is accomplished through changes in management process and in materials used.
WHY IS PRETREATMENT NECESSARY?
Many industries release wastewater into municipal sewer lines, which carry the wastewater into local or regional wastewater treatment facilities. Such treatment facilities remove many contaminants from wastewater, but are typically not designed for removal of high levels of industrial contaminants. If not removed from wastewater during treatment, these contaminants will then remain with the wastewater and be released into the environment. To ensure that Federal and State water quality standards are met, the Federal Clean Water Act passed in 1970 requires the U.S. Environmental Protection Agency (EPA) to ensure that effective pretreatment programs are established.
HOW ARE PRETREATMENT PROGRAMS STRUCTURED IN N.J.?
In many cases, the EPA delegated responsibility for pretreatment to the state. Responsibility has been further delegated larger wastewater treatment facilities in the state to develop, monitor and enforce their own pretreatment programs. The state remains responsible for pretreatment programs in smaller facilities in the state.
HOW DOES A PRETREATMENT PROGRAM WORK?
Each wastewater treatment facility responsible for a pretreatment program must set standards for pretreatment by conduct a "Head Works Analysis" utilizing EPA's guidelines.
In this analysis, the wastewater entering the plant (influent), the treated water which is discharged from the plant (effluent), air emissions, biosolids and key treatment point within the plant are assessed. These are statewide standards that govern the level of contaminants that can be released into the air, water and biosolids. A calculation is done to determine what level, or amount, of each contaminant that can be accepted in the influent which will enable the treatment plant to meet the required environmental standards.
These calculations are then submitted for review by the DEP. Once accepted, the facility then establishes the pretreatment requirement that will determine to what extent each industry must pretreat its discharge.
The facility has some discretion in meeting the requirements. It can reserve a "safety factor" of a percentage of allowable contaminants (typically 10-25%) in order to have a margin of safety or to allow for additional industries in the future. It can also allocate limits in several ways: 1) it can set uniform limits that are the same for each contributing industry, 2) it can tailor limits depending on the type of pollutants generated by each industry, or 3) it can allocate limits based on amount of flow, so that smaller companies, which have fewer resources for pretreatment, have somewhat less strict requirements than larger companies.
The local pretreatment limits that are set must be written in the form of a local ordinance and submitted to DEP for review. The DEP requires that the public be notified of the proposed ordinance, with an invitation to comment. If there is significant comment, a public hearing must be held by the sewage treatment facility in conjunction with the DEP.
HOW ARE PRETREATMENT LIMITS ENFORCED?
Most often, pretreatment limits are enforced by the treatment facility through National Pollutant Discharge Elimination System (NPDES) permits, or through sewer use ordinances. The EPA and the state act as back-up for these local agencies by providing legal and technical assistance if necessary. Additionally, citizens may bring suits against violators of standards. Historically, this has been done by interest groups rather than individuals.
HOW DOES THE PRETREATMENT PROGRAM RELATE TO THE POLLUTION PREVENTION ACT?
Industrial pretreatment requirements have, in many cases, resulted in pollution prevention practices by industries. Rather than installing initial or additional pretreatment systems within their plants, industries have chosen instead to alter their manufacturing process, thus eliminating the potential pollutant as well as the need for pretreatment.
HOW DOES INDUSTRIAL PRETREATMENT PROGRAMS OR THE POLLUTION PREVENTION ACT AFFECT BIOSOLIDS QUALITY?
By reducing or eliminating contaminants from the influent, there are less undesirable chemicals in the wastewater to be removed. As many of the contaminants, such as heavy metals, wind up in the biosolids, a cleaner influent will result in a cleaner effluent and cleaner biosolids. A look at biosolids quality since 1983 will demonstrate the effectiveness of pretreatment programs in improving biosolids quality.
This data, which reflects average biosolids quality throughout the state, demonstrates how pretreatment programs have improved biosolids quality. Continued enforcement will result in continued improvement, which will help to provide biosolids and biosolids derived products which will be of value to the end users and which will continue to safeguard the State's environment.
WHO CAN I CONTACT WITH QUESTIONS ABOUT INDUSTRIAL PRETREATMENT PROGRAMS?
You can call your local sewerage authority or wastewater treatment plant to determine if there are local limits or a local pretreatment program.
