On August 4, 2013, Friends of Penobscot Bay carried out pH testing of water and soils on both side of the first cove of Stockton Harbor near GAC Chemical.
( See photos of the pH tests being done here. (includes closeups of pH meters at sites.)
The tests were not intended to be conclusive. They were carried out to see if there are anomalies or changes in acidity of the soils and sediments tested at various distances from the abandoned sulfuric acid plant (the bldgs above the "6" in the photo below).
Test gear: Ferry-Morse "Electronic Soil Tester" and Luster Leaf's "Rapitest."
Narrative: The testing began on the end of the sandbar in the cove facing the old acid plant (1,2), crossed over the cove to the intertidal flats on the shore side of the cove (3,4), sampled three areas of the eroding bluff, (5,6,7) then the gravelly beach shoreline(8) and two areas of mudflats close to and "downstream" from the abandoned facility (9, 10) Area 10 was tested multiple times.
Results See photos of the pH tests being done here. (includes closeups of the pH meters at sites.) The pH was near neutral (pH 7) in areas 1, 2, 3, 4 & 5. A lower pH was found in site 6 above the concrete debris under the old sulfuric acid factory & storage tank. Acidity increased sharply in the gray eroding material at area 7 on the steep path leading from the shore to the old factory (pH 4.5 to 4.8). Readings in the gravelly beach & mudflat directly below Area 7 and bayward were as low as pH 2.2.
A great deal of sulfuric acid must have leaked from the old plant (believed to have been shut down in the early 1970s) and its storage tank for it to still be leaking into the soils and shores and the intertidal flats!