Observations/Finding

As requested, the site was visited by our AS Engineering and Consulting (ASEC) representative for the purpose of providing quality control inspection and testing services. Visual observation techniques were employed to verify compliance with project drawing/specifications, applicable codes, and materials submittals. The following observations were observed on site this day.

Our ASEC representative was on site to observe contractor (NG Grading) and the observation/testing of the placement of fill/backfill. The contractor removed topsoil from Lots #23 through #25. Topsoil was stockpiled and will be placed in a greenspace at a later time. Lots #23 through #25 was proof-rolled with a loaded off-road dump truck. No severe pumping and/or rutting was observed. This is a deep fill area where blasted rock material will be placed from the nearby pond (NW pond). The contractor began placing blasted rock material in approximately 1-foot lifts. This material consisted of rocks between 6 inches to 3 feet in diameter. Finer soils were mixed in with the blasts rock prior to placement. These lifts were compacted via a 815 sheep’s foot roller. It appears that the 815 sheep’s foot is breaking down the rock as it rolls over it. The contractor is benching into virgin ground going up the hill as the lifts are being placed. Our ASEC representative watched as loaded off road trucks rolled across the lifts to verify stability. Probe rod testing was also performed to check stability of surficial soils.

Drilling was performed in the northwest pond area, where the contractors drilled a total of 12 holes — 6 holes to a depth of 22 feet and 6 holes to a depth of 23 feet. Rock was encountered between approximately 5 and 8 feet below the ground surface in this area. The drilling was completed in an 8-foot by 8-foot grid pattern using a 3.5-inch diameter drill bit. Controlled blasting is planned to be performed on the following workday in this same area. As documented in the attached drilling log, the grid spacing was 8 feet by 8 feet. Based on standard field practices and prior experience, an overdrill depth of 3 feet was assumed for calculation purposes. If this assumption differs from the actual drilling method, please advise so that the calculations can be adjusted accordingly. Using these parameters, the total calculated volume of mass rock drilled for the day is estimated to be 367.41 cubic yards.

We appreciate the opportunity to be of service to you on this project. If you have any questions regarding this report, please feel free to contact us. We will be more than happy to discuss it with you.

lots 23 -25

blasted fill material

drilling

pond excavation

drilling

blasted rock and probe rod for scale