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f • 23 May 1996 AGE-NC Project No 95-0139 Page 4 of 4 h 7 76 to 10 28 feet bsg Between January and April 1996, ground water rose an average of 0 98 feet at the site _ The ground water flow direction continues to be north to northwest The gradient steepens from approximately 0 002 ft/ft at the southern onion of the site to approximately 0 005 ft/ft at the PP Y P northern portion of the site(Figure 3) The gradient and flow direction are similar to those measured ' during the January 1996 monitoring event ' 42 LABORATORY ANALYSIS OF GROUND WATER SAMPLES TPH-g and TPH-d were detected iri MW-1 at concentrations of 2,500 and 540 parts per billion (ppb, ' reported as micrograms per liter), respectively BTE&X were also detected in MW-1 at concentrations ranging from non-detect (ND) to 180 ppb (xylenes) Petroleum hydrocarbons were ' not detected in monitoring wells MW-2,MW-3 or MW-4 during the April 1996 sampling event The analytical results of the ground water samples are summarized in Table 2 The laboratory report (WEST Sample Log 14500) and chain-of-custody form are included in Appendix B 5 0. CONCLUSIONS AND RECOMMENDATIONS Concentrations of TPH-g and TPH-d in MW-1 decreased from the January 1996 monitoring However, petroleum hydrocarbon concentrations in MW-1 have fluctuated historically ' Petroleum hydrocarbons were not detected in MW-2, N1W-3 or MW-4 indicating that the plume remains sufficiently defined and "stable" at the site Ground water flow direction and gradient have ' remained consistent at the site over the past year The PHS-EHD may require performance of soil and ground water remediation feasibility testing at 1 the site Upon completion of feasibility studies, if required, a Corrective Action Plan for soil and ground water remediation should be prepared 6.0. LIMITATIONS Our professional services were performed using that degree of care and skill ordinarily exercised by environmental consultants practicing in this or similar localities The findings were based upon ' analytical results provided by an independent laboratory Evaluations of the geologic/hydrogeologic conditions at the site for the purpose of this investigation are made from a limited number of available data points(i a monitoring wells) and subsurface conditions may vary away from these data points No other warranty, expressed or implied, is made as to the professional recommendations contained in this report 1