PILLAR: Sustainable
AGENDA DATE: October 22, 2025
COUNCIL DISTRICT(S): 6, 8, Outside
DEPARTMENT: Dallas Water Utilities Department
PRIORITY: N/A
______________________________________________________________________
SUBJECT
Title
Authorize Supplemental Agreement No. 1 to the professional services contract with Halff Associates, Inc. to provide additional engineering services necessary for water and wastewater main installations at 21 locations (list attached to Agenda Information Sheet) - Not to exceed $883,900.00, from $1,281,170.00 to $2,165,070.00 - Financing: Wastewater Capital Improvement G Fund ($806,633.00) and Water Construction Fund ($77,267.00) (This item was deferred on October 8, 2025)
Body
BACKGROUND
On February 25, 2004, the City Council authorized a professional services contract with Halff Associates, Inc., to provide engineering services for the replacement and rehabilitation of water and wastewater mains in various locations. The original scope of the contract consisted of survey and design for approximately 80,500 feet of 8-inch through 21-inch diameter water and wastewater main replacements and rehabilitation in various locations, primarily within the Hickory Creek and Pleasant Grove sewer basins. Project locations were divided into two phases for design and construction. Phase 1 design and construction are complete. Bidding and construction of Phase 2 was delayed due to extended time required for necessary easement acquisitions, subsequent discussion of construction logistics with property owners from whom Dallas Water Utilities Department (DWU) has acquired easements, and to review the DWU 2020 Comprehensive Wastewater Collection System Assessment Update (CWWCSAU) and incorporate subsequent design modifications to accommodate flow capacity changes since the original design. Phase 2 was subdivided into Phase 2A, which is currently under construction, and Phase 2B, which requires further evaluation and additional design efforts.
Additional easement acquisition and construction logistic efforts along with additional flow capacity requirements have resulted in the need for additional investigation, engineering, coordination to update project surveys, basemaps, designs, construction phase services, and permits to enable the construction of both Phases 2A and 2B for approximately 35,451 feet of water and wastewater mains. The additional effort includes a re-alignment evaluation and subsequent survey, investigation, and design efforts for the replacement of up to approximately 11,510 feet of anticipated 12-inch through 30-inch wastewater main within the Hickory Creek drainage basin as part of Phase 2B. The existing main to be evaluated for re-alignment is a 12-inch diameter clay wastewater main built prior to 1984. It is located primarily within an easement, with limited accessibility in private property, and requires replacement due to its condition and limited capacity. The evaluation will allow the alignment selection to incorporate accessibility considerations for improved DWU long-term maintenance and operations. Replacement of the main with a new main of the required size will improve the capacity of the wastewater system, reduce the potential for Ssanitary Ssewer Ooverflows upstream, reduce Inflow and Infiltration, minimize service interruptions, and generally reduce maintenance and operational costs.
It is now necessary that DWU expand Halff Associates, Inc. scope of work to provide the additional engineering services because they are the most highly qualified firm with demonstrated competence due to their long-time engagement on the Hickory Creek project and their extensive work on Phase 1 and the design of Phase 2A. This experience provides them with an unmatched, comprehensive knowledge of the necessary and proposed wastewater improvements associated with this project. The additional services will ensure that design modifications can be made to address changed conditions and will provide necessary bid and construction phase services for both Phase 2A and 2B.
This action will authorize Supplemental Agreement No. 1 to the professional services contract with Halff Associates, Inc. to provide additional engineering services necessary for design work, permitting updates, and bid and construction phase services for Phase 2A, and additional work related to the realignment evaluation, preliminary design report update, survey and base mapping, design, easement surveys, geotechnical investigation, permitting and coordination, and bid and construction phase services for Phase 2B. The additional services will ensure that design modifications address changed conditions and provide necessary bid and construction phase services to procure and construct both Phase 2A and 2B projects. Delays in the replacement of existing wastewater mains will increase the risk of continued pipe deterioration, pipe collapse, inflow and infiltration, and inadequate pipe capacity hindering growth and causing sanitary sewer overflows.
ESTIMATED SCHEDULE OF PROJECT
Began Services May 2004
Complete Services June 2028
PRIOR ACTION/REVIEW (COUNCIL, BOARDS, COMMISSIONS)
On February 25, 2004, the City Council authorized a professional services contract with Halff Associates, Inc., to provide engineering services for the design and replacement or rehabilitation of water and wastewater mains in various locations by Resolution No. 04-0734.
On October 8, 2025, this item was deferred by Councilmember Lorie Blair.
FISCAL INFORMATION
|
Fund |
FY 2026 |
FY 2027 |
Future Years |
|
Wastewater Capital Improvement G Fund |
$806,633.00 |
$0.00 |
$0.00 |
|
Water Construction Fund |
$ 77,267.00 |
$0.00 |
$0.00 |
|
Total |
$883,900.00 |
$0.00 |
$0.00 |
Original Contract $1,281,170.00
Supplemental Agreement No. 1 (this action) $ 883,900.00
Total $2,165,070.00
Council District Amount
6 $151,293.48
8 $683,737.83
Outside $ 48,868.69
Total $883,900.00
LOCAL PARTICIPATION
|
Prime |
Status |
Workforce % |
|
Halff Associates, Inc. |
Local |
23.37% |
OWNER/EXECUTIVE
Halff Associates, Inc.
Jessica Baker Daily, PE, CFM, PMP, President and Chief Executive Officer
MAPS
Attached