The existing facility was constructed in the early 1980s with a permitted capacity of 36 MGD. Phase I of constructing the new facility focused on site preparation, and Phase II included the construction of the new plant. Improvements during Phase II consisted of upgrades to plant headworks, primary clarifiers, biological reactors, membrane bioreactors, (MBRs), UV disinfection, a effluent discharge system, chemical storage and feed systems, biosolids collection and processing systems, and odor control system and appurtenances. This advanced wastewater plant is the largest MBR facility in the United States. 

CERM provided the following services during both phases:

Phase 1, Engineering Services

CERM was subcontracted during Phase I activities to quantify the materials necessary to complete the site preparation and gain information about rock conditions for the partially constructed soil nail retaining wall. CERM accomplished the task by performing topographic surveys, subsurface exploration, and geotechnical evaluation of the soil and rock materials on site. CERM estimated the lateral and vertical extent of blasted rock on site as well as rock remaining for blasting by drilling soil testing borings, excavation test pits, and reviewing rock blasting records. CERM also confirmed the compaction of fill placed during grading in Phase I by reviewing compaction test results and performing independent tests.

Additionally, CERM’s engineering team estimated the amounts and types of materials removed from the site by performing a detailed comparative analysis of the grading plan, the initial existing conditions plan, and the revised existing conditions plan along with the subsurface exploration data.

Phase 2, Construction Management Services

CERM provided structural, mechanical and civil inspectors/field technicians, throughout construction. In order to ensure the general contractor’s adherence to the contract documents, CERM’s responsibilities included daily inspections and documentation of construction activities, review of material testing reports, review of drawings and specifications, and verifying the completion of all punch-list items during the close-out and commissioning phase.

Client: Parsons Water & Infrastructure Inc./DeKalb County Watershed Management

Market: Facilities