The lake that supplies drinking water to Brownwood in Central Texas was at historic low levels last summer, and the city looked for alternatives.

The most attractive turned out to be direct reuse — treating wastewater effluent to make drinking water. The city is proceeding with plans to build a direct-reuse treatment plant costing $6 million to $8 million.

Brownwood is a city of about 20,000 close to the geographic center of Texas. Its industrial base includes Kohler, 3M and Superior Essex plants that together employ about 2,200 people and need quality water to continue operating.

David Harris, director of utilities, is not concerned about any public revulsion over what some might label as "toilet to tap" recycling. For years, Harris and other city officials have made it a priority to keep their community informed about the importance of water and wastewater treatment systems. Now the city is reaping the rewards in public support for what on the surface would seem to be a controversial approach. Harris shared the city's experiences in an interview with Treatment Plant Operator.

How serious are the city's drinking water supply issues?

Harris: Most communities in Brown County get their water from Lake Brownwood, a 7,400-acre lake created in 1930. Last year, the lake reached its all-time low level. In spring, as it was getting drier and drier, we started water restrictions on irrigation — first Stage 1, then Stage 2, and finally Stage 3, which allows watering only one day a week for limited hours at night. We also started looking for other options for our water supply.

What alternatives were available?

Harris: There is no major or minor aquifer in the county near where we are. There are some shallow water sources, but they're not reliable — in a real drought, they quickly dry up. There is some salt water really deep down, but its quality is worse than ocean water. It's not really a viable option. There is an aquifer about 20 miles south of us. It has a lot of water and it's not too deep, but the water has radon in it at about seven times the EPA maximum level.

Another option was that the rules for using surface water say you can go a quarter-mile downstream of the wastewater treatment plant, and pull water out of the receiving stream and treat it. The problem is that then you get into water rights issues. Once that water comes out our 36-inch outfall into South Willis Creek, it becomes part of the waters of the state, and I don't own it. I would have to apply for water rights to get my water back.

Does the wastewater treatment plant produce water for reuse now? Is there a market for irrigation water?

Harris: We have a regional wastewater treatment plant that serves Brownwood, a prison, a youth correctional facility, and the City of Early, with a population of 2,800. The capacity is 4.54 mgd, and we now treat about 2.5 mgd. We reuse effluent on site for all plant functions, and we conserve 16 to 18 million gallons of potable water per year. As for irrigation, there are a lot of pecan orchards in the area, but none of them are close to the wastewater plant. There's a golf course, but it's about five miles away.

What led to the decision to explore direct reuse?

Harris: We have these major industries that need water and that we really can't afford to lose. It would almost destroy the town to lose those 2,200 jobs. When we looked at everything available to us, we saw that we had this beautiful, crystal-clear treatment plant effluent that just dumps into a little creek and goes away.

We have years and years of analysis on it. We have a 10-15-3 permit [BOD-TSS-ammonia]. We have a Carrousel system — an extended aeration oxidation ditch — with standard circular clarifiers and tertiary sand filters. We get some amazing quality water. Our ammonia is 0.1 to 0.3 mg/L, BOD less than 2 mg/L, and TSS from 0.5 to 1.5 mg/L.

The chemical analysis showed nothing of concern. We have a big industrial pretreatment program. We ran a test of our effluent against primary drinking water standards, just as it goes through the Parshall flume and out. We passed for everything except nitrates, which were about 24 mg/L, versus the standard of 10 mg/L. But that's treatable. We started looking at whether we could reuse that water.

How did you proceed with devising a direct reuse solution?

Harris: We hired an engineer who had done significant work on our wastewater treatment plant and did feasibility studies. We put some ideas together and met with the Texas Commission on Environmental Quality. We talked to half a dozen of their staff people and told them what we were thinking. They looked at us kind of glassy-eyed because nothing like this had been done before.

We showed them our analysis and our history. A lot of their people were familiar with our treatment plant. In working with them we found that direct reuse was feasible and that they would support it with some heavy regulation. The reuse plant would have to meet a very high standard. It would have to follow a multiple-barrier approach, which basically means you need redundancy on everything. For example, if a surface water plant would normally have one disinfection zone, we would have two, so that if one would fail we would still have full treatment. Really, we had to design two water plants but get credit for one.

What kind of treatment is envisioned for the effluent?

Harris: It will be membrane ultrafiltration followed by reverse osmosis (RO). We probably wouldn't need the RO to meet the requirements, but we included it for the public relations value and for the guarantee that we'll remove some of the constituents in wastewater that are not in surface water — the salt, dissolved solids and pharmaceuticals. The RO will pull those substances out, as well as the nitrates.

We'll have chlorine disinfection as well. Everything will be disinfected before we get to the filtration. We'll also have UV light treatment, which breaks down a lot of the microconstituents everybody is worried about, and also kills Cryptosporidium and Giardia. And we'll have activated carbon cartridge filters. Activated carbon is like the super-magnet for a variety of low-molecular-weight chemicals that might squeak through RO. It also helps with the taste of RO water. It's a very advanced system.

How would you describe the process of working with the TCEQ on this first-of-its-kind project?

Harris: We've been under a review-as-you-go process. We didn't want to get caught up in designing the whole plant, turning in a 500-page document, and then waiting six months for them to send 500 pages of questions back. We meet with them every few weeks and get their blessing on our methods of treatment. They want to approve the specific membranes and all the specific components. The review is very intense. We have already arranged for funding from the Water Development Board. Assuming we receive approval from the TCEQ, our city council will have to make the decision whether to proceed or not.

Will the city still use Lake Brownwood as its primary drinking water source?

Harris: Yes. The reuse plant will have a 1.5 mgd capacity, which equals about 30 percent of our annual running average water use. We will blend that with treated lake water to add some alkalinity, keep the corrosivity of the water down, and give it a more familiar taste.

How have you gone about getting the community on board with this project?

Harris: We talked to all the industries, who know they need water to keep their businesses open. It's the same with the schools. We have a college here in town and they want to water their athletic fields and play soccer.

I've spoken at meetings of Lions, Rotary and Kiwanis clubs, some of them multiple times, to explain what we're doing and why. I've been on the local talk radio station. We have a local newspaper and an online newspaper that people follow closely. We've had public meetings and presentations. At one meeting we showed an animated video on ultrafiltration. One of the review engineers from TCEQ came to town and did a presentation on the plant. Brownwood News Online recorded that on video and put it on YouTube.

What sort of credibility with the public did the city have going into this project?

Harris: Our community relations didn't start last spring. It started years ago. For years, we've done tours of the wastewater treatment plant. We take the freshman and sophomore biology classes from the high schools. Many students have toured the wastewater plant, some of the kids we trained years ago are now adults.

The Chamber of Commerce has a program called Leadership Brownwood. Each year, they select 25 to 30 people who are young professionals, mid-level managers at the industries, or college professors, and they go through a six-month program to learn about the community. They go to the water plant, the wastewater treatment plant, the landfill, city hall, the county courthouse. Every time we get new council members, we take them to all the locations, so they understand what we do.

What else have you done to teach people about water and wastewater?

Harris: I went to the store and got six bottles of water. I dumped five of them out in the yard. Then I went to the wastewater plant and filled a bottle with what comes in through the headworks. I filled another with water from the middle of the process, and another from after the clarifiers, and another after the sand filters. I also took a bottle of lake water.

Then I would show people. I've only had one person tell the difference between our wastewater effluent water and bottled water. When they look at it, they say, "I don't see why we can't drink it." With lake water, we're looking at about 8 to 15 NTU turbidity. Our plant effluent averages 0.68 NTU. So when I say "wastewater effluent," hundreds of people in town know what that is, and they talk to others about the presentations.

Have your community relations programs paid off in other ways?

Harris: Yes. For example, last year, when we had to restrict water use so severely that trees started dying and people lost their grass, they got concerned. They've really done well to do what it takes to conserve. They water plants with their bath water. They take the cold water they run before shaving and put it in jugs to water the trees. That's the level of community support we have. Last year we cut our water usage by 24.5 percent. I was amazed.

What's the main lesson your experience teaches about community relations?

Harris: When people see you doing what you say you're going to do, when you're open and honest, they trust you. If you give people all the information, they will generally make good decisions.