Dallas Water Utilities Department: Managing a Precious Resource

In the State of Texas, there’s only one naturally-occurring lake. Before the turn of the last century, the City of Dallas, Texas began developing and acquiring surface water supplies – eventually leading to Lake Ray Roberts, Tawakoni, Lewisville, Grapevine, Ray Hubbard, Fork and Palestine. In 1881, the city purchased the water system from the Dallas Fire & Hydrant Company for a hefty sum of $65,000 and – with decades worth of population booms – now serves 1.3 million Dallas citizens and another one million in nearly 27 area communities – totaling between 2.3-2.4 million people. By 1915, the city had grown significantly to require a wastewater collection system and the first of two sewage treatment plants.

“Expanded service area is one of the things that distinguish us from other water utilities – we’re not only providing a service to the city, but also surrounding suburban communities as well. Most water departments would be geared to providing service to just their city residents,” says Charles Stringer, Assistant Director for Water Operations. “Another significant feature is we solely operate off revenues we generate. As part of the City of Dallas, we obtain some of our essential support services from other city departments.”

Dallas Water Utilities’ operating budget to date is about US $530 million and its capital budget is US $300 million.

RESOURCES VS. GROWTH

Dallas Water Utilities (DWU) has three purification plants, built between 1930 and 1964: Bachman, Elm Fork and the East Side plant, which is currently under expansion. Collectively, they can treat more than one billion gallons of water per day for the Dallas area. Ozone technology is used as a primary disinfectant in the water treatment process and the East Side Plant is currently the largest ozone facility for treating water in North America, with a total of nine, 4,000 pound-per-day ozone generators.

Additionally, DWU owns and operates two wastewater treatment plants – Central and Southside – which have a combined treatment capacity of 300 million gallons per day. While there is currently sufficient water to support the Dallas area, this finite resource will not be able to sustain future growth without conservation, reuse and additional supply.

“One of our challenges here in the Southwest is the growing population. We expect Dallas to more than double, from 2.3 million to over five million, by 2060,” Stringer said.

Working for the City of Dallas the past 40 years as an engineer/chemist, he’s already witnessed the past population explosions firsthand. “In 1997, the State of Texas began the rolling five-year ‘State Comprehensive Water Plan’ to identify and develop additional water resources. Included as part of the State Wide Plan, the City of Dallas developed strategies to augment its future water supplies. These strategies include a combination of reuse, conservation and developing new surface supplies. Of all these strategies, the development of new reservoirs presents a significant challenge due to competing uses for land and water and organized opposition to new lakes in general.

Dallas Water Utilities is also looking at other options including partnering with other agencies in North Texas to bring new water into north central Texas such as possible water from out of state and the conjunctive use of groundwater. As Stringer puts it, “every stone is being turned.”

EDUCATION & CONSERVATION

Since 2001, Water Conservation has played an increasingly major part in helping to reduce water consumption and extend water supplies during periodic droughts. For example, there is a Dallas ordinance requiring rain and freeze sensors on irrigation systems and low flow toilet fixtures on all new and replacement commodes. Education through “Out Reach Programs” has enabled customers to save water through use of more efficient plumbing fixtures; by planting drought tolerant vegetation that needs little water, and providing rebates on household items such as low-flush toilets. Probably the most significant change that effectively lowered water consumption was when the City Council passed a City Ordinance restricting the use of lawn irrigation systems from 10:00 A.M. until 6:00 P.M. on weekdays, April 1st thru Oct. 31st. The city noticed a 50 mgd drop in water consumption immediately after this ordinance was adopted.

“We currently spend approximately US $3.6 million a year on our water conservation efforts. This includes advertising on billboards, media purchases for TV advertisements, educational outreach programs and rebate programs. A significant part of the public outreach program is geared toward the school system in Dallas and the surrounding area. DWU sponsors an annual “Poster Contest” which is a big hit among elementary school students. DWU also teamed up with the Sanitation Department to launch a program where the University of North Texas trains elementary through middle school teachers on both water conservation and recycling solid waste so that they can incorporate these topics into their school curriculum.

Dallas is also taking steps to control its unaccounted water losses in the distribution system. Several years ago, Dallas created a leak detection program that uses current state of the art technology to identify existing leaks in the distribution system. Through a combination of technologies including Permalog Leak Detectors, Leak Correlators, and Sahara Acoustical Leak Detection (PPIC), they are systematically checking over 4,000 miles of pipelines within the city of Dallas every five years. Utilizing another technology known as Eddy Current Detection, the department is able to determine the condition of all prestressed concrete cylinder pipe (PCCP) used in large water transmission lines. This technology has virtually eliminated all failures in large diameter pipelines.

Because of these strategies, Dallas has reduced its overall water consumption from 250 gallons per capita per day (gcpd) in 2002 to below 200 gpcd in 2009 – far better than originally expected.

FROM METHANE TO ELECTRICITY

Dallas Water Utilities’ efficiency efforts also extend to electricity, encouraged by Dallas’ Green Dallas Program Initiative, which mandates lower air emissions. The city’s overall goal is for a 30 percent reduction in electrical use from the 2007 baseline.

According to Jesse Dillard, Energy Manager for the City of Dallas’ Equipment and Building Services, “Going Green is now becoming more of a mindset in the city and NW Texas area. Dallas was the number one city in Texas for green procurement – 40 percent of its energy comes from renewable resources (mostly wind), but that title recently passed to Houston. We haven’t done much with solar yet – we feel it has a ways to go first.”

Recently, Dallas Water Utilities partnered on a co-generation facility with a private energy company that will take methane gas produced from sludge digesters at the South Side Wastewater Treatment plant and convert it into electricity. “We previously flared the methane into the atmosphere, but now will use it to create energy and save money in the process,” says Richard Wagner, Program Manager for Wastewater Engineering Facilities. “Ameresco is building and operating the facility on a 20-year lease agreement and will sell electricity back to Dallas at a rate lower than the grid. It’s a win-win situation”, Wagner says.

The department is also looking at other ways to produce and save energy. According to Stringer, “DWU will be looking into hydroelectric power at one of its water treatment plants and solar panels at other locations.”

INTO THE FUTURE

Behind the water department’s operations are over 1,450 experienced employees that receive continual training. Through a joint agreement with Freese & Nichols University, they join other city employees for continuing education courses relevant to their individual departments. In addition, the department has its own in-house training staff that is certified by the Texas Commission on Environmental Quality (TCEQ) to provide both water and wastewater Operator Certification Training for operations, maintenance and laboratory personnel.

Dallas Water Utilities, in conjunction with other city departments, frequently team together on design and construction projects that enhance the quality of life for Dallas citizens by beautifying community spaces around its lakes, parks and facilities through such amenities as bike and jogging paths, dog parks and nature areas. When possible, DWU works with the private sector to make beneficial use of old facilities such as abandoned pump stations and treatment plants by converting them into functional uses.

At the end of the day, The City of Dallas aims to be back on top as number one for green procurement in the state and its water utilities department will be looked upon for its continued service and innovation.

FACTS AT A GLANCE

COMPANY NAME: Dallas Water Utilities

OPERATIONS: Municipal water and wastewater utility

ESTABLISHED: 1881

EMPLOYEES: 1,450

REVENUE: $530 million

www.dallascityhall.com