characterization of the dredged spoil material will also be 

 necessary. 



Based on the observations made during the recent site visit, it 

 is our opinion that the storm drains along Charles River Avenue 

 should be cleaned out and examined for possible leakage of oil 

 into the surrounding soils through cracks. Visual evidence of 

 the oil stained soils at ground surface and the detected 

 concentrations of fuel oil in some samples are indicative of 

 localized areas of surface spillage and/or oil contamination in 

 the fill materials. During initial phases of site development 

 and particularly during site excavation, segregation of oil 

 stained material and contaminated fill would be advisable. 



During demolition of the on-site buildings, it will be 

 necessary to dismantle the above ground fuel oil storage tank. 

 It will be necessary to dispose of the empty storage tank at a 

 state approved storage tank disposal facility. Any oil 

 contaminated soils that may be uncovered during the tank 

 removal will also need to be segregated for disposal. Disposal 

 options for oily soils and excavated fill materials will vary 

 depending on DEQE policy at the time the material is 

 excavated. At present, we believe the fill material which 

 contains minor amounts of cinders, ash, wood, etc. and which is 

 not overtly contaminated by oil to be urban fill. Material 

 which exhibits overt evidence of the oil contamination would 

 require special handling and disposal at a landfill which will 

 accept such materials. Zones in the fill which contain 

 construction debris, large quantities of wood, cinders, ash, 

 etc. would likely be classified as solid waste, and would 

 require disposal in a DEQE approved sanitary landfill. 



Due to the chloride concentrations detected in the natural 

 soil, the excavated natural soils will need to be disposed of 

 at a DEQE approved coastal disposal site. The chloride content 

 of the saturated fill material may be similar to the natural 

 soil and also require disposal at a coastal disposal site. 



Because dewatering is anticipated during site excavation and 

 foundation installation, chemical testing of groundwater was 

 conducted to evaluate baseline groundwater quality. It is 

 anticipated that a National Pollution Discharge Elimination 

 System (NPDES) permit will be required for discharge of 



-20- 



AQK 



00 64 



