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� | / | | The ground water flow direction on 12/02/87 was directly ' towards the domestic well located about 140 feet northwestof the � | excavation. This probably resulted from pumpage from this well ; � the well is probably hydraulically connected to the water table | ^ � aquifer ( a well log is not available ) � ^ ! ` Th 454ZxV degree swing in the direction of ground water flow � between and is most likely attributable to either a � cessati -�/ot o�7pumpahe domestic- well , or the onset of heavy | oumpage from a nearby well to the east of the site. Since the ` magnitude of the gradient on 12/21 is twice that on 12/03, the / ` writer feels that most likely, the flow direction swing results | from heavy pumoage to the east of the site., This chance in the grouno water flow direction has apparently caused a regulatory problem at this site. The problem | stems from the requirement that a monitorzng well must be � ins�alle� and sampled down gradient from the source of contamination. Since the gradient has swung around , it is hard | / to tell just where down gradient is. Thus, plannLnq for a well . location is complicated . 1 / Recently, W. H. Fox II of WHF Environmental Consultants, remeasured the ground water level in these wells. The wells were � measured on 9/ 16 , 9/30 and 10/07/88. The writer constructed a ! three point problem to determine direction and magnitude of the ground water gradient. This time, there was even yet another / | ' solution to the problem which follows: | � 9/16 - 9/30 - 10/07 --- N 25 . 256 it / 100 +t . This rearesents an average of the three readings, the maximum � variation of which was 0. 07 ft. The readings for each of the ! three wells for each of the three days are shown in the apoerdix , along i'71. well readihgs for the measurements in December of 19S/ .DISCUS S!ON ` . ! ^ / The possible contamination at this site results from a ' � rupture of a 1500 gallon tank as it was being removed from the | | site. The writer nds, that appro tely120 to, 50gaIlons of moror o� � �� e '�ro��e~r��tured t ihtt�± o ca� oa 7 foot deep excavation. The spill was cleaned uo- by ~ excavation i of the soil in the bottom of the hole. ak_-about 15 � Minutes; the hole was deepened from 7 to 12 feet. During/, the ' deepening of the excavacion, ground water was encountered. / Approximately 4 cuoic yaros of material was excavated from the ! hble. Water from the bottom of the excavation was sampled . The lab results disclosew 39 ppm motor oil , 20 ppo benzene and 50 ppb xylene. The above was told to the writer by W. H. Fox if , who was | present at the time of the incident . l ( . � \ �