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77-510A Centurion Company -2- PuF.r_,t. 31 , 19i8 �-. . Mineral soils encountered in the borings were visually and - manually classified in the field by the crew chief in accor- ' `"'= dance with ASTM D2487 "Unified Soils Classification System" and ASTM D2488 "Recommended Practice for Visual and Manual !' Description of Soils". A copy of ASTM D2487 is attached. _1 All samples were then returned to the laboratory for veri- fication of the field classifications by a Soils Engineer. Representative samples will remain in this office for a period of 60 days to be available for your examination. Percolation tests were conducted in accordance with City of Orono procedures in the City of Orono Ordinance. Those pro- cedures indicate that 4 percolation tests are needed for the primary drain field area with 2 additional tests for drain field expansion area. Each of the boring completed was probed immediately after completion for the presence of groundwater, with a final ,i J probing conducted in each boring approximately 24 hours later. 1 Results • The Log of Soils encountered in the borings conducted and water level observations are shown on the attached Log of Boring sheets. Soil conditions throughout the tract are highly variable with silty clayey sand, clayey sand and sandy or silty clay till predominating. Slightly silty or silty sands were also encountered at various locations . Top- soil thickness is also quite variable, ranging from as little as 1-inch to 3 feet. Only three lots were accessible to power equipment to permit taking boring of sufficient depth to reliably identify the soils and open a large hole to permit repeated probing for groundwater. Dense trees and brush make the remaining areas j both inaccessible to conventional power equipment and make taking borings by hand methods extremely difficult because of the presence of roots . Our firm operates some large truck- mounted drill rigs which after some chain sawing of larger trees, could easily gain acces to all areas of the subdivision. This equipment,• however, would substantially clear a path as 7 it progresses through This would have very undesir- .J . able environmental a ecstatic 'mpact on the property at this time. It would not to, in all cases , select a path i which would need to be cleared for future driveways since the i location of driveways will be a decision left to future buyers i . of the individual lots. To prevent irrevisible damage to the property, we thus based our conclusions on borings taken, general soil map data, and an analysis of the topography. , ' Where borings were performed, groundwater was encountered only in Lot 12, at the 7 and 8-foot depths , corresponding toelevation 941-944. pr-71 I _1 1! I, - -" / 1 S E s f''.i C 4 a u::i 1