Operation H2O: Fracking yields tainted water that could be reused

Treatment of wastewater is much cheaper than desalinating seawater. 'We have a lot of water, but we don't use it well,' he said. Farms in the Central Valley, for example, often flood fields with freshwater to irrigate, but the process is so clumsy that most of the water does not feed plants. It's wasted. In addition, nitrates in the fertilizers pollute water that seeps back to the aquifer. 'Now we can't drink the water,' he said. 'We have poisoned the water.'

The one-use mentality squanders a relatively plentiful resource. 'We drink it, urinate it out and it goes back in the ocean. We're done,' Mr. Webley said. 'That's a real pity.'

Orange County's system takes 100 million gallons of black water a day, cleans it then runs it through reverse osmosis. The plant puts the resulting clean water, about 80 million gallons, into the aquifer. 'They end up with 20 million gallons of really nasty stuff,' Mr. Webley said, which has been pumped out into the ocean. 'The solution to pollution is dilution,' he said.

Enter Trevi Systems, with its experimental project funded by the Energy Commission grant. 'They give that to us now to clean up, that even nastier (input) than the reverse osmosis can do. Of that 20 million gallons, we're going to recover 15 million. Now you've got 5 million gallons of really, really, really nasty' stuff, he said.

If the project in Orange County goes well, Trevi plans to approach other municipalities such as Santa Rosa and Petaluma.

Starting in 2000, Santa Rosa, along with partners Rohnert Park, Cotati and Sebastopol, spent some $200 million to build a 40-mile pipe to send half the cities' wastewater for injection into the Geysers geothermal field in the northeastern corner of the county. The pipeline, done in conjunction with Calpine electrical generating facilities at the Geysers, was finished in 2004.Dual-purpose solar

Meanwhile, solar arrays could be an ideal partner for Trevi. Solar panels use only a third of the energy that lands on them to produce electricity. The rest of the energy is wasted in the form of heat. Dual-purpose arrays that produce electricity and capture the heat could be used by Trevi Systems in powering its forward osmosis. Several companies, such as Cogenra Solar in Mountain View, already make such dual-array panels. 'We're very keen to move forward, find a 10-acre lot, industrial-scale' for a solar farm, Mr. Webley said. 'You start making energy cheap.'

In states such as Texas, where the aquifer has become brackish due to drought, large dual-purpose solar arrays could be installed to generate electricity, with the heat going to desalinate the brine in wells, then use the water for irrigation or human consumption. 'There are markets everywhere,' Mr. Webley said.

Many industrial plants have excess steam from boilers that is disposed of in huge cooling towers; power plants generate waste heat that must be dissipated. All that heat can be reclaimed to run forward osmosis. 'We use a tenth of the electrical energy' compared to reverse osmosis, he said. 'I use a lot of free energy.'

Mr. Webley suggests requiring any business that uses water for processing to treat its own wastewater with a small plant before being allowed to discharge it. 'I would push the technology further upstream to the polluters,' he said. 'Part of permitting a factory is that you put in a water treatment plant right there that recycles 80 percent. You don't discharge the nasties into the municipal wastewater.'

By removing industrial wastewater from the system, municipal water treatment becomes significantly cheaper, he said.

Many companies release excess heat that can be harvested. For example, Lagunitas Brewing Company, also in Petaluma, uses steam to clean its tanks. 'Once that steam is done, it's flowing out of that tank, it's still damn hot,' Mr. Webley said. Using a heat exchanger, 'I take that heat as it comes off the tank cleaning. I use it to warm up my draw solution.' Now the steam is sent to a cooling tank, and heat is wasted. 'People don't even think about it,' he said.Heat from air conditioners

In hot climates, ubiquitous air conditioning units produce enormous amounts of heat. 'You're making more hot air than cold air. What do you do with it? You dump it,' Mr. Webley said. 'Give it to me.'

A big-box retail company based in the East Bay asked Trevi Systems for help as it installs stores in India, Mr. Webley said. 'They want to put a (dual-energy) solar array on the roof' of big stores to generate power, then use the heat to purify all the water going in and out of the store. 'Fascinating application,' he said. 'You could do it on a Wal-Mart.'

'In the Middle East, you don't have snow melt,' Mr. Webley said. 'You desalinate, take it or leave it. You have no choice.' There aren't many other sources of water, and 70 percent of the world's desalination is done in the Middle East. Trevi is working on new deals to use its technology for desalination in Saudi Arabia and other countries.

Energy for reverse osmosis in the Middle East is cheap, at roughly $4 a barrel to pump out of the ground. His pitch: switch to forward osmosis, sell the barrel for $100 instead of burning it. 'Maybe a third of the oil is getting burned to make power,' he said. 'Think of the opportunity cost of that lost revenue.'

Water is a political tool, according to Webley. 'We fight over water' between northern California and southern California. Because the cost of water is routinely subsidized, the true cost is difficult to ascertain. Water reclaimed by reverse osmosis is three to four times the cost of subsidized water.

Even by providing reclaimed water at twice the subsidized rate, Trevi has entered a tough business arena. But new markets are opening as drought squeezes freshwater supplies and pollution fouls existing water supplies. He loves contemplating the interconnectivity of man-made and natural systems, where complex problems provide potentially huge business opportunity.

'That's why I got into this business,' he said. 'There's a whole world under our feet in the drains.'

[caption id="attachment_101924" align="aligncenter" width="500"] Trevi Systems uses forward osmosis with a proprietary draw solution to tackle cleanup of brackish water, even black water from sewage pipes. Here is part of the Trevi Systems laboratory. (credit: James Dunn)[/caption]

Reverse osmosis vs. forward osmosis

Trevi Systems uses forward osmosis, coaxing water through a plastic micro-porous membrane into a chamber where clean water mixes with a proprietary 'draw' solution that is hygroscopic – it attracts water. The draw solution could be salt or silica gel – non-toxic materials.

After osmosis, when Trevi's proprietary mix – what Trevi's John Webley calls a 'unique organic molecule'– is warmed, typically using recaptured waste heat, the draw solution drops to the bottom and clean water can be pumped off the top. 'When you heat it up, it lets go of the water,' he said. The draw solution, food-safe and biodegradable, is reusable. Trevi replaces it about every two years.

What is the draw solution? 'I can't tell you, it's super-secret,' Mr. Webley said. 'What we call our secret sauce is this draw solution. Now you have beautiful, clean drinking water' no matter what the source, including seawater or black water from sewage pipes.

Salts, viruses and other impurities stay on the front side of the membrane, where they have to be removed and disposed of. The solids can be mined to reuse nitrates from fertilizers, as well as potassium, magnesium, lithium, salts and minerals. 'There are a number of salts in there that are very valuable,' he said.

The membrane fouls during the process, must be cleaned daily with sulfuric acid and anti-scaling substances, and lasts three to five years.

Reverse osmosis, the more common desalination method, gobbles electricity as high-pressure pumps propel water through semi-permeable membranes to extract salt and impurities.

Infrastructure capital costs of plants for reverse and forward osmosis are comparable. The economic edge that Trevi Systems seeks to exploit is in use of otherwise wasted heat energy. 'We are a process driven by waste heat,' he said. 'The heat I want (to purify water) is the heat you throw away. I make water at half the price.'Pharmaceutical designer molecules slip through membranes

What sneaks through both reverse and forward osmosis are pharmaceuticals, designer molecules so tiny that they can pass through the highly selective blood-brain barrier to be effective in humans. These include birth-control pills, antidepressants, heart and blood-pressure medications, and blood thinners. No osmosis membrane in desalination or routine water treatment catches these impurities. Reclaimed water will always have minute amounts of such meds unless a further process is used.

'That's the elephant in the room that no one wants to talk about,' said John Webley of Trevi Systems. 'They work their way through and they end up in the frogs, fish, fish eggs. You can buy fish in the store and I can show you the pharmaceuticals in there,' he said. Then we eat the food-borne pharmaceuticals 'and we're all now on birth control. That's why the fertility rate is dropping,' he said. 'The pharmaceutical load in our wastewater is the biggest problem.'

Japan and Germany are in the forefront of removing pharmaceuticals using hydrogen peroxide injected into water, then treating it with ultraviolet light, which shreds the molecules into hydroxyls (OH) that attack pharmaceuticals. Orange County has adopted such a process to dispose of pharmaceuticals. The treatment is energy-intensive and expensive. 'That's a bigger, nastier problem that the industry doesn't talk too much about,' Mr. Webley said.Fracking yields tainted water that could be reused

The process of fracking or high-pressure hydraulic fracturing of rock walls in oil and gas wells to spur their production has a byproduct of extremely salty water, according to John Webley, co-founder of Trevi Systems. The residual water contains about four times the salt of seawater.

To reclaim the water, 'you can't use reverse osmosis because the pressure is too high,' he said. 'You would break the membrane.'

Now well operators boil the water to clean it, burning up some of the energy produced from the wells. Or they take the highly polluted 'frack water' solution, truck it away and dump it down deep underground wells to keep it out of the aquifer. 'The deep well is reasonably safe,' he said, though they have been correlated in parts of Texas with earthquakes.

'The problem is, you took beautiful freshwater and buried it in the ground where it's never going to come out again,' he said. 'It would be lovely if you could take that water and reuse it at the well head.'

Forward osmosis could be used to clean up most of frack water, he said.John Webley: Telecom, other ventures1987: Co-founded Optilink1992: Co-founded Advanced Fibre Communications1999: Co-founded Turin Networks2004: Tellabs bought AFC for $1.9 billion2007: Founded Innovation Labs incubator, sold in 2012 to Thoroughbred Capital for $5.4 million