Plants both environmental and industrial thrive with water

Water Authority Process

The water authority takes very seriously its task of providing safe, clean water to consumers. While employing 20 staff members, someone is always on duty, checking and double-checking that everything is running smoothly and efficiently.

The process starts by acquiring surface water from the Brazos River, said Ronnie Woodruff, the water authority’s general manager. The water is then put through a complete treatment aeration process.

Next, the water authority tests for total carbon, adds coagulants and does a pH adjustment. Chlorine dioxide disinfectant is added to kill viruses.

Water then goes to three clarifiers, which are large-diameter sedimentation basins. Velocity is used to make sediment and mud settle to the bottom while the clean water rises to the top.

The last step the water goes through is its piping from the clarifiers to filters, which remove any leftover particles. Then the water authority adds chloramine, a compound made of chlorine and ammonia, and a corrosion inhibitor.

“All the chemicals that touch the water are NSF-approved,” Woodruff said. “Even the paints on the containers the water is stored in have been inspected and approved by the National Sanitation Foundation, which is the industry standard.”

A plant, such as BASF, on the other hand, can use almost half as much as the water authority just to run its own operation.

Environmentally conscious

Much like the water authority, BASF is very serious about clean water, even going so far as to return it to the Brazos River cleaner than when it first came out of the waterway, said Sunil Monga, BASF senior production manager of utilities.

The difference, however, is the site’s water comes from several different sources, including recycled city wastewater, and it is always looking for ways to become more efficient and thus reduce dependency on the area’s fresh water supply.

The site is contracted with Dow Chemical Co. to purchase raw water, then it is cleaned before use and then again before being recycled as wastewater.

BASF since 2014 has also contracted with the city of Clute to use its recycled wastewater. Putting the system and infrastructure in place to transport the water to BASF was estimated to cost about $2 million, in addition to paying the city of Clute for the water.

Before the collaboration, Clute would still clean its used wastewater but then would dump it back into the river, thereby wasting it.

“It’s a great thing,” Clute City Manager C.J. Snipes said. “As water becomes more scarce, I imagine more arrangements like this will come about between cities and plants.”

The resource already is scarce, considering the demand placed on the local supply.

“Believe it or not, we’re in a water-distressed area,” said Ron Barksdale, BASF site services director. “A lot of people think, ‘Well jeez, how can Freeport be a water distressed area if you guys get 48 inches of rain a year?’ The sad fact of the matter is most of the water that comes to this area comes from Central Texas, from the Brazos River basin. The rainwater we do get runs off into the Gulf of Mexico because there’s no reservoirs.”

Therefore, BASF is always on the lookout for effective water-reduction solutions.

“Energy use is directly connected to water use,” Barksdale said. “The more energy you use, the more heat you produce. To reduce heat, we use cooling water. Therefore, the more energy-efficient you become, the lower the water usage.”

This also reduces the plant’s carbon footprint, he said.

Similar to the water authority, BASF has a streamlined cleaning process for its incoming and outgoing water.

Cleaning process

The steps BASF follows in treating its wastewater include neutralization, reaction, clarification and chlorination/dechlorinization, according to a document provided by BASF officials.

During the process of neutralization, the wastewater has its pH adjusted to prepare it to be introduced to the biomass or microbes, also called bugs. If the pH of the water is not just right, it can be detrimental to the health of the bugs.

The next step is the reaction process, which is a bio-treatment step. The contaminants are consumed by the bugs, which have a steady diet of oxygen and the waste found in wastewater. Given enough time, the bugs will consume nearly all of the contaminants in the water.

Next is the clarification process. Once all of the contaminants have been removed, the water still is cloudy or hazy from individual particles, known as having a very high turbidity, so it has to be clarified in a clarifier to remove the suspended solids that remain in the water.

The final step of cleaning up the wastewater is to chlorinate the water to kill any remaining bacteria and then to dechlorinate the water to make the water suitable to discharge. This is similar to how some may clean an aquarium.

The Freeport site has multiple layers of protection to prevent anything from going wrong that could violate BASF’s wastewater permits. The first layer is known as the Wastewater Risk Assessment.

The risk assessment involves proactively studying every production unit at the site looking for any risks of harmful substances that might make it into the wastewater and subsequently mitigating that risk. If something out of the ordinary is found, the risk is analyzed and handled.

Another protective measure is the large basin that contains any and all contaminated wastewater streams prior to entering the treatment plant.

And finally, as a backup to the first two layers of protection, the influent and effluent of the treatment plant are continuously monitored and analyzed to ensure no contaminants have entered the wastewater. This security measure also helps to ensure all treated wastewater adheres to TCEQ permit requirements before being deposited back into the Brazos River.

Hurdles and solutions

At BASF, a company built from a German foundation, the policy follows the European water stewardship program, Barksdale said. In doing so, the site tracks its water usage very closely and often brings people together to discuss water conservation projects, then executes those projects.

One such water-utilization project is BASF’s new ammonia plant — the site’s newest addition.

“We bring the recycled city of Clute wastewater in and process it,” Monga said. “Sometimes we use reverse osmosis to further purify the water. The water is either used for the cooling system as process water or used to make steam through the boiler system. The water used to make the steam needs to be very pure.”

The site can store about 4 million gallons of wastewater and process it at a slow, comfortable pace.

Another solution BASF has looked into is collecting rainwater, however, it found it would require a very large storage basin.

BASF always is looking into ways to optimize water processing.

As for the water authority, the biggest hurdle it has faced was the drought in 2011 because the river levels were so low and more was coming out than being put back, Woodruff said.

“In order to prevent this sort of thing from being a hurdle in the future, we have a new project in the works,” he said.

Water desalinization, the process of extracting brackish groundwater, and reverse osmosis of deepwater are being considered as a way to extend the supply of available water during a drought.

“So far, we’ve drilled one deep well and we’re in the process of drilling another one,” Woodruff said. “It is a $40 million project that so far is fully funded by reserve funds.

“It isn’t costing taxpayers any money.”

Snipes, during his career as a city manager, noticed a similar collaboration with a city to send another entity its wastewater, he said.

“The first time I saw this done was with a golf course,” Snipes said. “Using recycled water for manufacturing, landscaping and watering lawns is the best way to conserve our shared precious resource.”