The East Orange Water Reserve – 100 Years of Wellhead Protection
Vincent W. Uhl
Uhl, Baron, Rana & Associates, Inc., 243 North Union Street; Lambertville, NJ 08530,
609-397-9161, 609-397-9165, vuhl@vuawater.com
Since the early part of the 20th century, the City of East Orange, New Jersey has derived its water supply from a Water Reserve located approximately 7.5 miles west of the City along the Passaic River. Currently, four major wellfields within the water reserve produce approximately 10 million gallons per day (MGD). These four wellfields, the Braidburn, Dickinson, Canoe Brook and Slough Brook, have a total of 18 production wells in service. Twelve wells derive groundwater from a sequence of unconsolidated glacial outwash deposits referred to as the Buried Valley Aquifer System and six wells are completed in fractured bedrock comprised of sandstone, shale and basalt.
The Water Reserve comprises 2,300 acres of woodlands, wetlands, and the flood plains of Canoe Brook, Slough Brook and the Passaic River surrounded by populated suburban areas. It is essentially undeveloped, although a golf course, roads and rights-of-ways for utility lines lie within its confines. For nearly 100 years, the Water Reserve has served to:
· Protect the quality of the underlying aquifer systems by providing a buffer between the wellfields and the surrounding land uses (industrial, commercial and residential) that can impact groundwater quality.
· Maintain natural recharge capacity to the underlying aquifer systems and provide areas that can be used for artificial recharge.
· Provide access to existing wells for operation and maintenance and to new sites for replacement production wells,
The first available water quality data for a wellfield within the Water Reserve were collected in 1905. Long-term chloride, total dissolved solids and hardness water quality data were evaluated to assess the impact of land use changes within the watersheds of the four wellfields on groundwater quality. The 1950’s and 1960s represented a period of rapid development in the area surrounding the water reserve. The chloride concentration in the water supply has increased six-fold since 1961. Total dissolved solids (TDS) concentration in the water supply has shown a steady rise over the past four decades and an increase in concentration of around 80 percent. Hardness of the water supply has also increased.
Twenty years of volatile organic compound (VOC) data were evaluated to access concentration trends and potential sources of very low VOC levels in certain wells in the Water Reserve. In the delivered water, only trace concentrations of trichloroethylene (TCE) and tetrachloroethylene (PCE) have been detected with any regularity. An analysis of VOC concentration since 1987 shows a decreasing trend for both PCE and TCE. Unlike many surrounding communities, and due to the beneficial effects of the Water Reserve, the City of East Orange has not had to treat its water for VOCs.