Then, in 1992, an engineering analysis called for three monitoring wells to be installed south of the reactor.

The Energy Department has 48 monitoring wells at the site and recently began drilling nine deep wells.

Tests from seven monitoring wells indicate benzene has not spread beyond the plant's boundaries.

The report really starts to get interesting when it comes to the pair of deep monitoring wells that the EPA installed in 2010.

Tests of shallow monitoring wells at five vineyards detected two pesticides, but in amounts the department said were below limits for drinking water.

Residents want the environmental department, which observes the monitoring wells, to provide them with monthly reports on its findings.

Nonetheless, in recent months methane levels have often been high at 2 of the site's 19 monitoring wells.

EPA constructed two deep monitoring wells to sample water in the aquifer.

Plant workers have drilled 9 monitoring wells and are drilling 14 more.

In December 1996 the contractor set up about a dozen monitoring wells on both properties to try to determine the extent of the contamination.