In the 1970s, a leukemia cluster was observed among the children of East Woburn, Massachusetts. Subsequently, contamination of the groundwater drinking water supply by organic pollutants, PCE and TCE, was found. Woburn became a National Priority List site (Superfund site) and was examined in great detail by EPA, USGS, consultants, etc. Before all the final hydrogeologic studies and assessments had been completed, a civil suit against 3 companies was brought by the law firm of Jan Schlictman (trial had to occur before final studies due to statute of limitations running out). The trials and tribulations of the case can be read (A Civil Action by Jonathan Harr) and seen (A Civil Action movie with John Travolta - however, the movie does not show much of the science).

The trial became a battle against lawyers and expert witnesses. Extensive data was presented and interpreted very differently by expert witnesses (geologists and hydrogeologists). Two companies, Beatrice Foods and W.R. Grace, were potentially liable for the pollution (the third company, Unifirst, had settled out of court before the trial). Beatrice Foods owned the tannery on the opposite side of the Aberjona River from the drinking water wells (Wells G and H). W.R. Grace, although on the same side of the river, was further away and underlain by lower permeability material.

Over 100 wells were installed in the Aberjona aquifer and water levels monitored with and without Wells G and H pumping. Remembering the general rule to draw groundwater flow lines perpendicular to water table contour lines, try to follow the path of the pollutants from the two possible sources, Beatrice and W.R. Grace, with and without pumping of the wells.

On the maps:

Beatrice Foods is the owner of the tannery and the 15 acres in the southwestern portion of the map.

W.R. Grace is identified as WRG in the northeastern portion of the map.

Pine Street to the south is the location of the leukemia cluster.

Without Wells G and H pumping, flowlines can be seen to bring groundwater from W. R. Grace past the wells into the Aberjona River. Groundwater from the 15 acre site flows into the Aberjona River.