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.

On this day, excavation, placement, and backfilling of storm drain components were conducted from CE3 to CE1, terminating at ST 0.00. Notably, the section between CE3 and CE2 traversed beneath the future road and entrance to the development. Challenges arose due to water intrusion during the installation process, particularly at Manhole CE-2.

Key Events:

1. Excavation and Placement:
   • Storm drain was excavated, placed, and backfilled from CE3 to CE1, terminating at ST 0.00.
   • CE3 to CE2 section encountered water intrusion.
   • Recommendation made to add a bedding of 6 inches of 57 stone to support CE-2 was not followed, despite probing indicating a shallow soil depth with natural rock beneath.
   • CE3 was placed with approximately 6 inches of 57 stone bedding.
2. Pipe Installation:
   • Between CE3 to CE2, 24-inch Reinforced Concrete Pipe (RCP) was used without rubber gaskets due to fitting issues.
   • Two 24-inch sections of pipe were sealed from the inside using waterproof hydraulic cement, with the remaining sections sealed with mortar. Concerns were raised regarding the waterproofing capability of mortar, but no remediation was observed.
3. Backfilling and Compaction:
   • Backfilling of the storm drain section was completed with approximately a 3-foot lift.  A recommendation was made to use smaller lifts, but not followed.
   • Compaction was not performed, preventing testing from being conducted.
4. Ductile Iron Pipe Removal:
   • A piece of Ductile Iron Pipe between 4.3 to 4.4 had to be removed due to blasting activities on the previous day altering the elevation.

Used instead of gaskets on 2 storm drain pipes E2-E3

used instead of regular gaskets NON-waterproof material used inside to seal remaining storm drain pipes E2-E3

storm drain

E2 storm drain manhole

termination of storm drain to roadway

E2 manhole

4.3 to 4.4 sanitation sewer

4.3 to 4.4 sanitation sewer