Salado Creek

12 new permits =
8 million gallons of wastewater per day

The Texas Commission on Environmental Quality is currently reviewing or has already approved permits for 12 facilities that could discharge 8 million gallons of treated wastewater (aka sewage) into Salado Creek, a pristine stream that flows over the Edward Aquifer Recharge Zone in Bell and Williamson Counties.

Salado Vista’s permit problems

Save Texas Streams urges you to submit comments to TCEQ on the Salado Vista draft permit by February 23. Go to the TCEQ online comment form at https://www14.tceq.texas.gov/epic/eComment/ and enter permit number WQ0015664002. These are the key problems with this permit: 

• TCEQ’s draft permit for Salado Vista says that its discharge outlet will drain into South Darrs Creek, which is outside the Salado Creek watershed. But the permit also says that the Salado Vista facility will be at a location on Hackberry Road that drains into Salado Creek, according to online maps for both TCEQ and the Texas Parks and Wildlife Department. Discharge permits draining into Salado Creek must have stricter limits.

• Instead, TCEQ’s draft permit for Salado Vista has some of the worst limits of all 12 pending and approved permits on Salado Creek. The Salado Vista permit has the highest limits for BOD (10 milligrams per liter) and TSS (15 milligrams per liter). And it has no limit at all for Total Phosphorus, which is the key ingredient in treated wastewater that’s caused massive algae blooms elsewhere.

• Pristine streams like Salado Creek have very low levels of naturally occurring phosphorus. When treated wastewater with more phosphorus is discharged into a pristine stream, it fertilizes excessive algae growth. This has already happened on the South San Gabriel River below the discharge outlet for Liberty Hill’s treated wastewater. How does TCEQ know that its draft permit for Salado Vista won’t lead to the same kind of algae outbreak on Salado Creek?

• Has TCEQ calculated the total impact on Salado Creek’s water quality if it approves all 12 discharge permits, or is it only considering each permit on a case-by-case basis?

At risk: a pristine stream & the Edwards Aquifer

TCEQ has already approved 5 of the new wastewater discharge permits, and it’s currently reviewing the remaining 7. Salado Creek is an exceptionally pristine and spring-fed stream, and it will not be able to handle 8 million gallons of treated wastewater per day. Because the creek has little to no flow during dry months, it will essentially be transformed into a sewage drainage ditch. The 12 approved and pending permits on Salado Creek represent one of the highest concentrations of new wastewater permits anywhere in Texas.

Several of the pending wastewater discharge permits are also in the Recharge Zone of the Edwards Aquifer. In 1996, TCEQ banned new wastewater permits in the Edwards Recharge Zone south of the Colorado River. If that ban had included the full extent of the Recharge Zone north of the Colorado River, most of the current discharge permit applications couldn’t have been filed. Also, while TCEQ still issues TLAP irrigation permits in the southern extent of the Edwards Recharge Zone, it only approves one type of dispersal method — surface spray irrigation — but not the other — subsurface drip irrigation. TCEQ's rationale for not approving subsurface drip over the Recharge Zone is the same reason it doesn't issue wastewater discharge permits in this area — in order to protect the water supply for millions of Texans who get their water from wells drilled in the Edwards Aquifer.

The South San Gabriel Warning

The problems with the pending permits on Salado Creek would be exacerbated by the inadequate treatment requirements that TCEQ has drafted for them. In particular, these pending permits would have very high or no limits on the amount of phosphorus that could remain in wastewater after it’s been treated and before it’s discharged. Phosphorus is a plant fertilizer, and adding more of it to pristine streams with very low amounts of naturally occurring phosphorus will fertilize the growth of excessive algae.

This has already happened in Williamson County west of Georgetown. The South San Gabriel River, which is also a pristine stream with little phosphorus, has been blanketed with excess algae for several miles below the point where Liberty Hill discharges its treated wastewater, which contains higher levels of phosphorus (see photo montage below). The draft permits that TCEQ has written for the pending applications on Salado Creek would allow treated wastewater to be discharged with 15 to 100 times more phosphorus than what’s in the creek. And while Liberty Hill was only discharging around 1 million gallons of treated wastewater into the South San Gabriel, the 11 existing and pending permits on Salado Creek could potentially discharge up to 8 million gallons per day.

Comparing permit limits

Carbonaceous Biochemical Oxygen Demand (CBOD) — This is an indirect measure of how well wastewater has been treated. A high CBOD level means that the discharged wastewater will deplete a higher amount of dissolved oxygen in a stream, which can lead to fish kills.

Total Suspended Solids (TSS) — This is also an indirect measure of how well wastewater has been treated. 

Ammonia Nitrogen (NH3) and Total Nitrogen (TN) — Ammonia in discharged wastewater can break down into harmful nitrites and nitrates.

Total Phosphorus (TP) — Because phosphorus fertilizes the growth of plants, a high TP level in discharged wastewater can fertilize the growth of excessive algae in streams with very low levels of naturally occurring phosphorus, such as Salado Creek.

* Permit information compiled by Mike Clifford, technical director, Greater Edwards Aquifer Alliance (GEAA)