The Mirant Plant...

Mirant people want potable groundwater to use with the plants scrubbers

The MD Public Service Commission has recently ruled on Mirant’s request for the use of the county’s groundwater as the water source for its proposed scrubber technology at its Morgantown facility. They are recommending that Mirant use either Potomac River water or wastewater from the La Plata WWTP. However, some use of groundwater from both the Patapsco and Patuxent aquifers would be permitted during an interim period during which, either or both of the above options are being developed.

During this period, as much as 1.3 mgd of lower Patapsco water would be allowed and .42 mgd of Patuxent aquifer water.  But this period would expire on August 1, 2010, or—“whenever the La Plata wastewater is delivered”.

These decisions were based in part, on the county’s concerns about its future groundwater supply, and a policy that the Patuxent aquifer must now be reserved for its future growth, and industrial users should therefore consider using wastewater or the River. But analysis of test wells drilled into the Patuxent aquifer at both Morgantown and Chalk Point also revealed that this aquifer is a very poorly productive one in this part of the county. Since its transmissivity is very low, any large water demand will create a major cone of depression at each site that in turn, would extend a considerable distance outwards and consequently limit the county’s future use of this aquifer. In particular, it was noted that the Patuxent wells in the Bryans Road area, 19 miles from Morgantown, could also be affected and be depressed as much as 100 ft. Use at Chalk Point could add another 50 ft., thus depressing Bryans Road Patuxent  wells 150 ft. 

Also, the report notes another benefit from the use of La Plata wastewater, namely the improvement of the Port Tobacco River’s quality, which now receives the town’s wastewater and is recognized as an impaired stream in need of remedial action.

So the State’s analysis and recommendation are noteworthy, and it will be interesting to see how Mirant responds.

Footnote: CBCC sent letters to the MD Public Service Commission and MDE on February 27 protesting Mirant’s use of groundwater for its scrubber application and recommended that either River water or wastewater be used for this operation. Noted was the fact that the county’s wastewater was already being used by the Panda-Brandywine power plant, a distance of 15 miles from the Mattawoman WWTP.

--- Arthur F Krueger