The York County Solid Waste Authority operates a ground water remediation
system at the York County Sanitary Landfill in Hopewell Township, Pennsylvania.
The site is listed on the Superfund National Priority List. The remediation program
is designed to capture ground water that has been impacted by the site, treat
ground water before it leaves the site and to maintain a piezometric barrier that
will prohibit the migration of contaminated ground water beyond the borders of
the site. This is achieved by the strategic placement of 17 recovery wells. It
is important to maximize the cone depression around the remediation wells in order
to prohibit offsite migration of ground water. A change in seasonal precipitation
may cause the yield of individual wells to vary significantly. A Subgard is used
in each recovery well to maintain the design depth to water. A pump is first sized
to handle the maximum expected yield, or maximum historic yield, from a well.
A Subgard is installed several feet above the pump intake. A constant depth to
water can be maintained by recirculating water back to the well during times of
low well yield and less as the yield increases. This use of Subgard reduces labor,
maintenance and wear of the pumps. The York County Sanitation Landfill has been
utilizing Subgard in its ground water remdiation program since 1985.