Vol. 7 No. 3 Winter 1999
A Newsletter About New Jersey's Water Quality Programs

The Division of Water Quality recently issued a new final NJPDES General Permit for Construction Dewatering discharges. The permit was issued as "final" in September 1999. Many in the state's construction and pipeline installation industries have anxiously awaited the development and issuance of this general permit.

The new permit authorizes discharges of groundwater that result from lowering the groundwater table during construction. Historically, these types of ground water discharges have not been regulated under individual permits because they are typically short-term in duration. This short duration is substantially less than the term of an individual NJPDES permit which is usually effective 5 years. The type of discharges subject to this general permit only need authorization for the time the discharge will take place.

In developing this general permit, the division intends to effectively regulate these discharges without setting unreasonable, burdensome conditions or requirements for dischargers and without creating an undue administrative burden for the division. Issuing individual permits for these types of discharges would be resource intensive to the extent of being impractical without having any recognized environmental benefit. Dischargers often notify the division on a case-by-case basis of these planned discharge events and have received determinations, in most cases, that a permit would not be necessary provided appropriate protective measures are taken.

A review of files and historical monitoring data from these types of discharges indicates they are typically "clean in nature." The pumping associated with well point construction dewatering for the purposes of lowering the groundwater table tends to stabilize the well packs, resulting in higher solids removal efficiency in the discharge.

The new general permit authorizes the discharge of groundwater, during construction dewatering, that contains negligible levels of pollutants. As such, the permit does not cover discharges from sites known or suspected to contain contaminated groundwater, such as remediation or petroleum products clean-up sites, stormwater discharges, and discharges associated with sediment laden waters (authorized under the Standards for Soil Erosion and Sediment Control in New Jersey and the Soil Erosion and Sediment Control Act N.J.S.A. 4-24-39 et seq). Exclusions also include discharges associated with treated or untreated domestic wastewater, combined or sanitary sewer overflows, filter backwash operations, hydrostatic test water discharges, contaminated groundwater discharges from aquifer or well pump tests, swimming pool discharges, tank and vessel bottom waters, and tank and vessel bottom and cleaning waters.

In accordance with N.J.S.A. 58:10A et seq., this general permit includes Best Management Practices (BMPs) and/or provides temporary treatment units as well as self-monitoring rather than numeric limitations.

No application submittal to the division is necessary for this permit, however, qualifying dischargers must submit a Request for Authorization Certification form 14 days prior to the anticipated discharge date. For copies of the Request for Authorization Certification form and/or the general permit requirements, please contact the Bureau of Permit Management at (609) 984-4428. This information can also be accessed from the division's web site at: www.state.nj.us/dep/dwq/forms.htm.

If you have any questions regarding this new general permit, Jim Grob of the Bureau of Point Source Permitting Region 2, at (609) 292-4860.