Request for Proposals - Engineering Services - Wastewater Collection System Basins 6 & 7 Rehabilitation Project Design, Construction Management and Related Services

The City of Sandy, Oregon (“City”) requests proposals from qualified consultants with experience related to wastewater collection system rehabilitation to perform design and services during construction for the Sandy Collection System Rehabilitation Project Basins 6 & 7 and related services.

The City has embarked on an ambitious program to improve its wastewater collection, conveyance, and treatment system. The Wastewater System Facilities Plan (WSFP, 2019) identified improvements to be implemented in three phases through 2040. This project was identified in the WSFP under Phase 1 improvements.

The collection system is comprised of approximately 47 miles of main and trunk line piping, over 4,500 service laterals 1,170 manholes and six pump stations. The system is primarily composed of PVC and concrete pipe ranging in age from 0 to 70 years.

The collection system experiences large swings between dry weather and wet weather flows due to Infiltration and Inflow, (I & I). This project is intended to reduce or eliminate I & I in basins 6 & 7 which during initial and ongoing collection system flow monitoring were identified as the second greatest source of I & I in the collection system. Basins 6 and 7 are comprised of approximately 45,00 LF of sewer main, 174 manholes, 45 mainline cleanouts and over 800 service laterals.