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' 20 April 2006 • AGE-NC Project No. 95-0106 Page 3 of 4 4.0.-, SUMMARY AND CONCLUSIONS ; The following conclusions were drawn.from the results of-the site investigation: ; On 1.8 March 2006,the groundwater elevation was between 32.81 feet and 33.75 feet above- '. ..; � � , MSL; which is an increase of approximately 0.60 feet since the December 2005 momtormg event.-Ground'water was inferred to flow towards the north at a gradient:of between 0.002 ' ftlft and 0.008 ft/ft,which is consistent with the historical flow pattern.' • TPH-g and the BTEX compounds benzene,ethylbenzene and xylenes were detected only in ' ground water sample MW-4, at concentrations of 140 µg11, 2.6 µg11, 8.6 pg/l and 2.7 Pg/l, respectively.. Only.benzene, at a concentration of 2.6 µg11; exceeds. DHS-established Maximum Contaminant Level of LO µg11 in drinking water. • The fuel additive 1,2-DCA was not detected in the March 2005 ground water samples; the fuel additive MTBE has not been detected in site ground water since December 2003. iThe concentrations of petroleum hydrocarbon contaminants have been consistently.declining in the impacted site-ground.'Water monitorin "wells MW-i and MW-4 since the abrupt increase of contaminants in these wells in 2001 (Figures 4 and 5);for the second consecutive , . quarter, petroleum hydrocarbons have not been detected in well MW-1: Based on the declining contaminant concentrations, the Weldon Church site appears to be successfully remediating by natural attenuation. RECOMMENDATIONS Based on this and previous site investigations,natural attenuation appears to be successfully reducing the concentrations of contaminants at the site.AGE recommends continued quarterly monitoring of the well network; if the declining concentration trends.continue for the next several quarters,.AGE recommends,preparatiori-of a closure report for the site. The next quarterly monitoring event,is ' ..scheduled for June 2006. ' 6A. 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 hydrogeologic ' conditions at the site for the purpose of this investigation are made from a limited number of available data points (i.e.,monitoring wells and ground water samples) and subsurface conditions ' Advanced GeoEnvironmental,Inc.