The Texas population is projected to almost double over the next fifty years. This population boom will greatly increase demand for the resources that make Texas such a popular place to work and live. The question Texas faces is: how best to meet the growing demand for water as the population expands? A cost-effective answer to that riddle – and the one most environmentally sustainable — is this: cities can recycle their municipal water supplies and reap many additional benefits at the same time.
Eagles at John Bunker Sands Wetland Center
Water for Texas cities is drawn from water supply lakes and aquifers, sent to water treatment plants, then piped into our homes and businesses. Much of the water is used on our lawns and lost to evaporation. The part that goes down the drain is captured and piped to a wastewater treatment plant. There it is cleaned enough to be released into creeks and rivers. Downstream cities impound some of it and use it for water supply.
With water recycling, instead of sending the treated wastewater downstream, it is reclaimed and re-used locally. The reclaimed water is subjected to advanced purification techniques that make it clean enough to be put back into our water supply. A portion of Texas’ water supply is already recycled – and there’s potential to recycle a whole lot more.
There are two major ways that water is recycled. One is by filtering it through specially created wetlands; the other is using high-tech membranes combined with other advanced processes in specialized facilities to purify the water.
East Fork Wetland is adjacent to John Bunker Sands Wetland Center south of Dallas
With wetland filtration, the wetland acts as a natural filter to remove waste products from the water. A great example is the East Fork Wetland adjacent to the John Bunker Sands Wetland Centerjust south of Dallas, managed by the North Texas Municipal Water District (NTMWD). There, water is pumped from the Trinity River into a beautiful 2000-acre constructed wetland. As the water flows through the wetland, aquatic plants take about 70% of the ammonia, phosphorous, nitrogen, and other waste products out of the water and use them as nutrients. Bacteria and sunlight also contribute to the cleaning process. After 7 to 10 days, the water is pumped back into Lake Lavon, increasing NTMWD’s water supply and improving water quality and the aquatic habitat of the lake.
A side benefit to municipalities is that wetlands are great habitat for birds and wildlife and a beautiful area for public recreation, community education, and research. Another advantage is that wetlands require less land than a reservoir. The East Fork Wetland, when fully operational, will produce almost the same amount of water that Lake Lavon produces each year, with less than one-tenth the acreage.
The other major approach to recycling water begins with membrane filtration. Membranes with microscopic pores – a tiny fraction of a micron in size – remove bacteria, viruses, and other harmful organisms. After filtering, the water is subjected to ultraviolet light and chemicals that are already used in water treatment. These carefully-monitored advanced purification processes result in water that is cleaner than most of what we drink today. One membrane technology, reverse osmosis (R/O), which is sometimes used by bottled water companies, results in water that is similar to distilled water. Water from reverse osmosis is so pure that producers of bottled water who use R/O often add salts back to the water to improve the flavor.
Drought-stressed cities in West Texas, such as El Paso, Big Spring, Brownwood, and Wichita Falls, are using or planning purification plants of this type to stretch limited resources. As the population grows in other areas, advanced purification plants will become an ever-more-sensible solution for meeting future demands for water supply.
Recycling water is a great way to help meet the growing demands for water as Texas’ population grows. It usually costs less than water from other sources and can be implemented more quickly than developing a new supply. It uses less land than building a new reservoir and benefits the environment. And as water use grows, the amount of water available for recycling will also grow. Even with some of the water from our wastewater treatment plants being released downstream to keep rivers flowing and provide fresh water for bays and estuaries, there will be a large amount of water available through recycling to meet future demands.
To be water wise, cities in Texas need to do three things – practice and promote sensible conservation within our own communities, especially when watering outdoors; maximize use of our existing water; and RECYCLE our municipal water supplies.
The future of wise water management is happening now. The policies and infrastructure we install today will be the foundation for the lifestyle and economy of our growing communities in the future. Let’s be sure that that foundation is a strong one by re-capturing, re-using, and recycling water.