TRA Wastewater Services

DALLAS-FORTWORTH,TX

Funding for the future: Trinity River Authority extends wastewater service in booming Dallas-Fort Worth Metroplex

Neel-Schaffer continues to be a leading player in the growth of the Dallas-Fort Worth Metroplex.

In a $6.5 million project, Neel-Schaffer designed and managed the construction for the extension of the Trinity River Authority’s Denton Creek Regional Wastewater System (the Authority) to service the burgeoning suburbs of Argyle, Flower Mound and Northlake in Denton County.

In 2008, TRA hired Cheatham & Associates, now a part of Neel-Schaffer, to provide an alignment study for the project, including the feasibility for each City. The firm developed a technical report from that study defining a wastewater treatment system and related costs.

This project was unique and innovative in terms of its funding. The Authority has limitations on bonding capacity in areas where service is not yet established. This project extends sewer interceptors to primarily undeveloped property and low-density member cities. However, the property is prime for major growth and development over the next five to 10 years.

Through a series of developer agreements with the three member cities, two major master planned developments provided the upfront funding required for the project. This funding will be credited back to the developments as the project develops with impact fee credits. Our technical report and feasibility study provided the basis for establishing the funding agreements. We provided an instrumental role in meeting with the stakeholders and developing a feasibility strategy that met the requirements of all parties.

In 2013, the project was complete, with a new lift station, 10 meter stations and nearly 18 miles of new sewer lines.

Our team provided the surveying and civil engineering design services as well as the construction management for Segments C, C-1, C-2, D, and D-1. Civil engineering services included the gravity interceptor design, boring, tunneling, geotechnical engineering and meter station design.

Surveying services included design survey, plats and legals, and subsurface engineering services. Environmental services included an EPA Phase I Assessment, and USACE permitting.

Segments C and D consist of approximately eight miles of gravity interceptors that will serve as the main trunk line of the Graham Branch Tributary located in the Towns of Argyle, Northlake, and Flower Mound. The gravity sewer pipe ranges in size from 42 inches diameter to 15 inches diameter and includes 10 meter stations. The system outfalls into the lift station at Cowboy Lane that will pump the sewage through a force main to the Denton Creek Regional Wastewater Treatment Plant.

Design for this system included PVC pipe as the base bid and an alternate bid for fiberglass in the larger diameters. The plan also included a tunnel at two locations (UP Railroad and FM 1171) and borings with steel casing at five other highway and interstate locations.