City of Westminster – Dewatering & Water Treatment Solution for Interceptor Sewer Improvements

Owner:  City of Westminster

GC:  Brannan Construction Co.

Engineer: HDR Engineering, Inc.

Project Revenue: $1,150,000.00

Project Time Period: January 2019 to November 2019

The Challenge

Comprehensive upgrades to the Little Dry Creek Basin system were needed because of aging infrastructure and pressing capacity issues. Griffin provided dewatering of open cut and trenchless boring sections of the pipeline.  The groundwater required treatment for TSS and various metals to meet stringent State discharge requirements.

The Solution

Multiple drilling methods were required to install the wellpoint dewatering system in the varying conditions along Little Dry Creek.  The varying geology resulted in flow rates ranging from 20gpm to 200gpm. Griffin designed and installed a transfer pipeline system to convey water from the dewatering zones to a centralized treatment system.

Griffin engineered a water treatment solution that incorporated oxidation, filtration, and several different types of media. Griffin’s experienced field technicians operated the dewatering and treatment systems concurrently to maintain optimal performance from the system.

The Griffin Difference

The highly variable soil conditions required a comprehensive dewatering design and specialized drilling methods to complete the installation.

Griffin installed and hydro-tested the treatment system and provided on-going site assistance to ensure seamless operation and compliance with the discharge permit.  Regular monitoring and preventive maintenance were conducted during the entire project to ensure optimal system performance.