Officials are hoping to ease Texas’ expected water shortage with a source you might find surprising.
Texas’ population is expected to more than double to about 46 million by 2060, bringing an increased demand for water.
However, water is a finite resource – there is only so much out there on the Earth’s surface and beneath the ground.
Water conservation is one powerful way to help address the problem. But another helpful tool you might not have
considered is the use of treated wastewater, known as effluent.
Effluent is the end product of the sewage treatment process. Of course, there might be a certain “yuck factor”
when one thinks of wastewater. But the final product undergoes a rigorous treatment process between when it enters a plant as raw sewage and when it can be safely
reintroduced into the environment as effluent.
Generally, when wastewater enters a plant, solids are removed through several steps. Bacteria are used
to further break down waste materials; odor is greatly reduced and harmful microorganisms are killed over several days or even weeks.
The remaining liquid is then filtered, further reducing odor and other undesirable qualities.
Finally, chlorine is used to disinfect the water. The chlorine is then neutralized and oxygen is added before the effluent is returned to the environment.
Typically, effluent is released into streams where it blends with other water to become part of the water cycle.
Effluent can be used in several ways to help cope with looming water shortages. For example, it can be used for irrigation
and landscape watering that would normally prove a drain on regular drinking water supplies.
The City of Abilene uses effluent to water grasses and other vegetation in its roadway medians as well as a local golf
course, says Jim Forte, Brazos River Authority planning and development manager.
Officials with a Waco area regional waste treatment system are also working on a similar plan, which would
send effluent to a local industrial park and golf course to be used for its landscaping.
“Reuse (of treated wastewater) allows you to do two things,” Forte said. “It gives you access to a water
source that traditionally has not been available. It can also extend the life of a water treatment plant by reducing its load in summer during peak usage.”
Another place where effluent can be substituted for regular water supplies is in energy production. Power plants,
whether coal, gas or nuclear, require water to run the turbines and for cooling. For instance, the City of Cleburne sells effluent to a power company to use for cooling at
a gas-fired power plant.
Effluent can also be used to boost an area’s treated water supply. The Authority has signed an interlocal agreement
with Abilene to allow the city to use the Brazos River to send effluent to join the city’s source for public water.
When Abilene puts the plan into action, effluent discharged into the Clear Fork of the Brazos will travel
downstream to intake pipes and then will be pumped into Hubbard Creek Reservoir, which Abilene uses for its municipal water supply.
From there, the lake water will go through the city’s water treatment plant to bring it up to state and federal
quality standards for residents to drink.
Under state law, in the Texas Water Code, effluent reuse is treated differently depending on whether the
entity that produced it uses ground or surface water as its water source.
In the case of surface water, when the effluent enters a river or other stream, it is considered state water.
Those downstream with senior water rights, allowing them to have priority over others to access water, can appropriate the water to use.
However, effluent that originates as groundwater is not subject to appropriation by senior rights holders and
the producer of the effluent keeps the water rights.
Whatever the source of the effluent, it will certainly play a vital role in helping take the pressure off traditional
sources of water. With a growing population consuming Texas’ limited water supply, such alternative sources will be an important tool for water planners in the future.