PILLAR: Sustainable
AGENDA DATE: May 27, 2026
COUNCIL DISTRICT(S): 2, 6
DEPARTMENT: Dallas Water Utilities Department
PRIORITY: Infrastructure
______________________________________________________________________
SUBJECT
Title
Authorize Supplemental Agreement No. 1 to the professional services contract with Hazen and Sawyer, P.C. to provide additional engineering services for the Harry Hines and Webb Chapel Extension Wastewater Interceptors Project (list attached to Agenda Information Sheet) - Not to exceed $2,045,015.00, from $3,264,998.00 to $5,310,013.00 - Financing: Wastewater Construction Fund
*In alignment with Water and Wastewater Capital Improvement Program.
Body
BACKGROUND
On September 12, 2018, the City Council authorized a professional services contract with Hazen and Sawyer, P.C. to provide engineering services for the design, replacement, and rehabilitation of water and wastewater mains at 5 locations. One of those locations included the replacement and rehabilitation of the existing Brook Hollow Wastewater Interceptor System that is in poor structural condition and needs additional capacity to support ongoing and future development. During design, the Dallas Water Utilities Department (DWU) completed the Comprehensive Wastewater Collection System Master Plan and recommended a larger interceptor to handle projected future flows. It was determined that the current corridor for the Brook Hollow Interceptor did not have sufficient depth to accommodate a larger interceptor as proposed in the Master Plan. Therefore, a new wastewater interceptor was proposed at Harry Hines Boulevard to accommodate the increased flows and provide additional capacity. The proposed interceptor was divided into segments, including the Harry Hines Interceptor Phases 1 through 4 and Webb Chapel Extension Interceptor.
The proposed improvements to the Webb Chapel Extension Interceptor include replacement of the pipeline and modification of two existing junction boxes into flow diversion structures prior to the construction of the Harry Hines Interceptor Phase 1 through 4. This will allow DWU to reduce the potential for sanitary sewer overflows in the Bachman Lake area and meet Texas Commission on Environmental Quality requirements.
This action will authorize Supplemental Agreement No. 1 to the professional services contract with Hazen and Sawyer, P.C. to provide additional engineering services necessary for the Harry Hines and Webb Chapel Extension Interceptors Project. The additional services will consist of geotechnical evaluations, a Geotechnical Baseline Report, updating the design based on new geotechnical information and master planning recommendations, bid phase services, and additional construction phase services. Improvements will consist of an estimated 25,900 linear feet of pipeline installation and rehabilitation, and when completed will increase the capacity of the wastewater system and reduce maintenance costs and sanitary sewer overflows.
ESTIMATED SCHEDULE OF PROJECT
Begin Services July 2026
Complete Services November 2027
PRIOR ACTION/REVIEW (COUNCIL, BOARDS, COMMISSIONS)
On September 12, 2018, the City Council authorized a professional services contract with Hazen and Sawyer, P.C. to provide engineering services for the design, replacement and rehabilitation of water and wastewater mains at 5 locations, by Resolution No. 18-1282.
FISCAL INFORMATION
|
Fund |
FY 2026 |
FY 2027 |
Future Years |
|
Wastewater Construction Fund |
$2,045,015.00 |
$0.00 |
$0.00 |
Original Contract $3,264,998.00
Supplemental Agreement No. 1 (this action) $2,045,015.00
Total $5,310,013.00
Council District Amount
2 $1,361,277.17
6 $ 683,737.83
Total $2,045,015.00
LOCAL PARTICIPATION
|
Prime |
Status |
Workforce % |
|
Hazen Sawyer, P. C. |
Local |
17.86% |
OWNER/EXECUTIVE
Hazen and Sawyer, P.C.
8150 North Central Expressway, Suite 700,
Dallas, Texas 75206
Alan Stone, PE, Chief Executive Officer
MAPS
Attached