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M98168GE • . enhances water accumulation and subsequent migration to the founda- tion soils. Improperly placed backfill will allow water to migrate along the utility trench or backfill areas to gain access to the subgrade support soils with subsequent mobilization of the swell or settle- ment mechanism resulting in movement of the supported structure. Backfill placement techniques of existing structural members. concrete structural members be cent backfilling. should not jeopardize the integrity we recommend recently constructed appropriately cured prior to adja- 11.0 SURFACE DRAINAGE The foundation soil materials should be prevented from becoming wetted after construction. Poet construction wetting of the soil support soil materials can initiate swell potential or settlement potential as well as decrease the bearing capacity of the support soil materials. Protecting the foundation f-om wetting can be aided by providing positive and rapid drainage cf surface water away from the structure. The final grade of the ground surface adjacent to the structure should have a well defined slope away from the foundation walls on all sides. The ability to establish proper site surface drainage away from the structure foundation system may be influenced by the existing topography, existing structure elevations and the grades and elevations of the ground surface adjacent to the proposed structure. We suggest where possible a minimum fall of the surface grade away from the structure be that which will accommodate other project grading constraints and provide rapid drainage of surface water away from the structure. If there are no other project constraints we suggest a fall of about one (1) foot in the first ten (10) feet away from the structure foundation. Appropriate surface drainage should be maintained for the life of the project. Future landscaping plans should include care and attention to the potential influence on the long term performance of the foundation and/or crawl space if improper surface drainage is not maintained. Downspouts and faucets should discharge onto splash blocks that extend beyond the limits of the backfill areas. Splash blocks should be sloped away from the foundation walls. Snow storage areas should not be located next to the structure. Proper surface drainage should be maintained from the onset of construction through the proposed project life. 19 ~iambert ana ~,o~ociates COMWLTIMO O[OTlCMMIC~L IMOIM!!q HMO Y ~TlMtt fE3TIM0