PILLAR: Sustainable
AGENDA DATE: June 24, 2026
COUNCIL DISTRICT(S): Citywide
DEPARTMENT: Dallas Water Utilities Department
PRIORITY: Infrastructure
______________________________________________________________________
SUBJECT
Title
Authorize Supplemental Agreement No. 5 to the professional services contract with Carollo Engineers, Inc. to provide additional engineering services for water quality improvements at the Bachman Water Treatment Plant - Not to exceed $490,629.00, from $10,727,425.00 to $11,218,054.00 - Financing: Water Capital Improvement G Fund
*In alignment with Water and Wastewater Capital Improvement Program.
Body
BACKGROUND
In June 2006, the Dallas Water Utilities Department (DWU) initiated a two-part study to investigate the cause of water quality concerns in parts of the water delivery system. The study and requisite testing confirmed that the treated water chemically changes as it moves through the water distribution system. Recommendations included process changes, design, construction, and implementation of improvements at all three water treatment plants to improve water quality and deliver stable treated water into the distribution system.
On June 23, 2010, the City Council authorized a professional services contract with Carollo Engineers, Inc. to perform engineering services at the Bachman Water Treatment Plant (WTP) for water quality improvements. The Bachman WTP was constructed in the late 1920s and underwent expansions in 1936, 1948, and 2006. The plant can treat 150 million gallons of water per day and is Dallas’ only water treatment plant located within the city limits. The completed efforts have provided significant water quality improvements, leading to more stable water in the distribution system for areas served by the plant.
Supplemental agreements have been authorized since the award of the original contract to complete additional evaluations, provide final design improvements, prepare construction plans and specifications, and to provide bidding and construction phase services. Multiple supplemental agreements have been necessary to align with DWU capital improvement schedules and budget constraints and to ensure the scope of final design and construction phase services were well defined.
This action will authorize Supplemental Agreement No. 5 with Carollo Engineers, Inc. to provide additional engineering services for final design, bidding, and construction phase services associated with the Liquid Ammonium Sulfate (LAS) Facilities and Clearwell Mixing Improvements Project at the Bachman Water Treatment Plant. These improvements will convert existing facilities from gaseous ammonia (a hazardous chemical system) to a LAS system, which is a better system from an operational and safety perspective for both employees and surrounding neighborhoods. Improvements will also provide better disinfection chemical mixing to ensure safe drinking water in the distribution system. Carollo Engineers, Inc. has submitted an acceptable proposal to complete these engineering services, and DWU recommends that their existing contract be amended.
ESTIMATED SCHEDULE OF PROJECT
Began Servies June 2010
Complete Services July 2028
PRIOR ACTION/REVIEW (COUNCIL, BOARDS, COMMISSIONS)
On June 23, 2010, the City Council authorized a professional services contract with Carollo Engineers, P.C. to provide engineering services for the Bachman Water Treatment Plant water quality improvements by Resolution No. 10-1640.
On March 28, 2012, the City Council authorized Supplemental Agreement No. 1 to the professional services contract with Carollo Engineers, P.C. for additional engineering and design services for the Bachman Water Treatment Plant water quality improvements by Resolution No. 12-0951.
On August 14, 2013, the City Council authorized Supplemental Agreement No. 2 to the professional services contract with Carollo Engineers, Inc. (formerly Carollo Engineers, P.C.) for additional engineering services associated with water quality improvements at the Bachman Water Treatment Plant by Resolution No. 13-1334.
On June 25, 2014, the City Council authorized Supplemental Agreement No. 3 to the professional services contract with Carollo Engineers, Inc. for additional engineering services related to water quality improvements at the Bachman Water Treatment Plant by Resolution No. 14-1049.
On August 12, 2020, the City Council authorized Supplemental Agreement No. 4 to the professional services contract with Carollo Engineers, Inc. to provide additional engineering services for water quality improvements at the Bachman Water Treatment Plant by Resolution No. 20-1164.
FISCAL INFORMATION
|
Fund |
FY 2026 |
FY 2027 |
Future Years |
|
Water Capital Improvement G Fund |
$490,629.00 |
$0.00 |
$0.00 |
Original Contract $ 1,163,554.00
Supplemental Agreement No. 1 $ 6,296,114.00
Supplemental Agreement No. 2 $ 1,240,754.00
Supplemental Agreement No. 3 $ 1,039,653.00
Supplemental Agreement No. 4 $ 987,350.00
Supplemental Agreement No. 5 (this action) $ 490,629.00
Project Total $11,218,054.00
LOCAL PARTICIPATION
|
Prime |
Status |
Workforce % |
|
Carollo Engineers, Inc. |
Local |
9.73% |
OWNER/EXECUTIVE
Carollo Engineers, Inc.
B. Narayanan, President and Chief Executive Officer
MAP
Attached