PLUMSTED TOWNSHIP

PLUMSTED MUNICIPAL UTILITIES AUTHORITY

What is the impact of the discharge on homes in the Woodlands Manor subdivision?

The MUA must comply with a NJDEP requirement that a groundwater discharge shall not result in mounding that will encroach upon a wetland or surface water, basement or other property (Technical Manual for NJPDES Discharge to Ground Water Permits, Page 15, Table 3, June 2002). The preliminary hydrologic model used to determine this predicts a discharge of 250,000 gallons per day (gpd) during an extremely wet season as was experienced in 2009/2010 may raise the ground water level in the northern area of Warwick Drive less than 0.1 feet and approximately 0.6 feet in the southern Warwick Drive/Success Road area (for more background on this, please refer to the Van Cleef Memorandum dated July 14, 2010 posted on the MUA’s web site at www.pmua.net). This amount of ground-water mounding could slightly extend the duration of high water-table conditions at four to five existing homes in the Woodland Manor subdivision, but would likely not be distinguishable from natural water-table fluctuations. 

The model used in predicting the conditions in and around the proposed recharge area is accepted by the NJDEP and the hydro geologic community. This model, however, was based on preliminary tests to establish the aquifer properties. While this data is believed to be an accurate representation, further extensive testing is proposed to fully understand the subsurface conditions and aquifer properties. Upon completion of this testing, the magnitude and duration of any impact will be further quantified as part of the final model for the site.

If it is determined the 250,000 gpd discharge will have an impact as outlined above, to comply with the NJDEP requirement of no negative impact, the MUA has several workable options.  One is to reduce the ground water discharge so there is no impact on the surrounding dwellings. The MUA may also be able to locate or design the infiltration ponds planned on the private parcels involved so that more of the water is discharged to the southwest, away from the Woodlands Manor subdivision. Other options might be site specific solutions such as curtain walls or swales to route or lower the ground water levels as a result of the discharge to naturally occurring background conditions or levels. The MUA will not know which option(s) to implement or whether any action is necessary until all the additional testing and modeling necessary for design and permitting has been completed. The PMUA does not expect to have this answer until later this year or the early part of 2011. The PMUA will continue to provide work progress updates at its monthly public meetings.