Title
Resolution to Approve a Professional Services Agreement with OHM Advisors (OHM) to Design the Odor Control System for Solids Handling Building Truck Loading at the Water Resource Recovery Facility (WRRF), RFP 25-55 ($265,904.00)
Memorandum
Your approval is requested for a Professional Services Agreement with OHM Advisors (OHM) in the amount of $265,904.00 for professional engineering services to design the Odor Control System for Solids Handling Building Truck Loading at the Water Resource Recovery Facility (WRRF).
An odor study for the Ann Arbor Water Resource Recovery Facility (WRRF) area was performed in 2018 and 2019 by HDR, Michigan, Inc. (HDR) to address ongoing nuisance odor complaints from WRRF neighbors. The odor study included review and evaluation of available data for the WRRF and surrounding area, sample collection and analysis of air samples from potential odor sources, assessment of the effectiveness of the WRRF existing odor control systems, air dispersion modeling to assess how odors may migrate within the study area based on geographical and climatic conditions and an objective assessment of where odors are likely to exist at nuisance levels.
The HDR report identified two areas at the WRRF that potentially cause offsite nuisance odors under certain meteorological circumstances. These locations include the Screen and Grit Building and the Solids Handling Building’s truck loading area. A new odor control system was designed and construction was completed and was placed into service in 2024 as part of the Headworks Improvement Project.
The design and Installation of an odor control system for the Solids Handling Building’s truck loading area (UT-SN-22-05) is included in the City’s Capital Improvement Plan (CIP) beginning in FY26. RFP No. 25-55 was prepared seeking the services of a professional engineering firm to review existing operations, collect additional data and information, propose an odor control system and prepare contract documents for an odor control system for the Solids Handling Building truck loading area.
On December 4, 2025, the City received three proposals for this work. The RFP required each consultant to submit a statement of qualifications including past involvement with similar projects, work plan, fee schedule, and resumes of personnel that they proposed were qualified and available to work on the Odor Control System for Solids Handling Building Truck Loading Project. WRRF staff reviewed the proposals and determined which firms were most quailed to perform the required services. The firms were evaluated and scored on the following criteria:
• Professional Qualifications (20%)
• Past Involvement with Similar Projects (30%)
• Proposed Work Plan (30%)
• Fee Proposal (20%)
After evaluation of the proposals, fee proposals for all three firms were opened. After further evaluations, it was determined that OHM provided the best proposal and best qualified project team at a competitive price.
WWTP staff is requesting your approval of a Professional Services Agreement with OHM in the amount of $265,904.00 and a contingency of $26,000.00 to provide professional engineering services for the design and bidding phase of the Odor Control System for Solids Handling Building Truck Loading project.
OHM complies with the requirements of the City’s Non-Discrimination and Living Wage ordinances.
Budget and Fiscal Impact: The City of Ann Arbor Capital Improvements Plan (CIP) includes the WRRF Odor Control System for Solids Handling Building Truck Loading (UT-SN-22-05). Funds to finance this contract are included in the approved FY26 Sewage Disposal System Capital Budget
.Staff
Prepared by: Anne M. Warrow, P.E., Wastewater Treatment Services Engineer
Reviewed by: Jordan Roberts, Public Services Area Administrator
Approved by: Milton Dohoney Jr., City Administrator
Body
Whereas, An odor study for the Water Resource Recovery Facility (WRRF) area was performed in 2018 and 2019 by HDR, Michigan, Inc. (HDR) to address ongoing nuisance odor complaints from WRRF neighbors;
Whereas, The HDR report identified the Solids Handling Building’s truck loading area as a potentially cause of offsite nuisance odors under certain meteorological circumstances;
Whereas, The design and Installation of an odor control system for the Solids Handling Building’s truck loading area (UT-SN-22-05) is included in the City’s Capital Improvement Plan (CIP) beginning in FY26;
Whereas, Through RFP No. 25-55, WRRF staff solicited proposals for professional engineering services to design the Odor Control System for Solids Handling Building Truck Loading;
Whereas, After WRRF staff evaluated proposals and fees, it was determined that OHM Advisors (OHM) is the best qualified engineering firm to provide the professional services requested in RFP No. 25-55;
Whereas, OHM’s proposed fee of $265,904.00 is reasonable to perform this work;
Whereas, WRRF staff request that Council approve a contingency of $26,000.00 to fund additional necessary services as approved by the City Administrator;
Whereas, OHM complies with the requirements of the City’s Non-Discrimination and Living Wage ordinances; and
Whereas, Funds are available in the Sewage Disposal System Capital Budget;
RESOLVED, That City Council approve a Professional Services Agreement with OHM Advisors (OHM) in the amount of $265,904.00 to provide professional engineering services to design the WRRF Odor Control System for Solids Handling Building Truck Loading as requested in RFP No. 25-55;
RESOLVED, That Council approve a contingency of $26,000.00 to fund additional necessary services as approved by the City Administrator;
RESOLVED, That the Mayor and City Clerk be authorized to sign the agreement after approval as to substance by the City Administrator and approval as to form by the City Attorney; and
RESOLVED, That the City Administrator be authorized to take all necessary actions to implement this resolution.