Sun-powered desalination for villages in India — MIT News

April 28, 2015
Solar desalination plant via MIT

Solar desalination plant via MIT

Here’s the release from MIT (David L. Chandler):

Around the world, there is more salty groundwater than fresh, drinkable groundwater. For example, 60 percent of India is underlain by salty water — and much of that area is not served by an electric grid that could run conventional reverse-osmosis desalination plants.

Now an analysis by MIT researchers shows that a different desalination technology called electrodialysis, powered by solar panels, could provide enough clean, palatable drinking water to supply the needs of a typical village. The study, by MIT graduate student Natasha Wright and Amos Winter, the Robert N. Noyce Career Development Assistant Professor of Mechanical Engineering, appears in the journal Desalination.

Winter explains that finding optimal solutions to problems such as saline groundwater involves “detective work to understand the full set of constraints imposed by the market.” After weeks of field research in India, and reviews of various established technologies, he says, “when we put all these pieces of the puzzle together, it pointed very strongly to electrodialysis” — which is not what is commonly used in developing nations.

The factors that point to the choice of electrodialysis in India include both relatively low levels of salinity — ranging from 500 to 3,000 milligrams per liter, compared with seawater at about 35,000 mg/L — as well as the region’s lack of electrical power. (For on-grid locations, the team found, reverse-osmosis plants can be economically viable.)

Such moderately salty water is not directly toxic, but it can have long-term effects on health, and its unpleasant taste can cause people to turn to other, dirtier water sources. “It’s a big issue in the water-supply community,” Winter says.

Expanding access to safe water

By pairing village-scale electrodialysis systems — a bit smaller than the industrial-scale units typically produced today — with a simple set of solar panels and a battery system to store the produced energy, Wright and Winter concluded, an economically viable and culturally acceptable system could supply enough water to meet the needs of a village of 2,000 to 5,000 people.

They estimate that deployment of such systems would double the area of India in which groundwater — which is inherently safer, in terms of pathogen loads, than surface water — could provide acceptable drinking water.

While many homes in India currently use individual, home-based filtration systems to treat their water, Wright says after consulting with nongovernmental organizations that work in the area, she and Winter concluded that village-scale systems would be more effective — both because fewer people would be left out of access to clean water, and because home-based systems are much harder to monitor to ensure effective water treatment.

Most organizations working to improve clean-water access focus their attention on controlling known pathogens and toxins such as arsenic, Wright says. But her analysis showed the importance of “what the water tastes like, smells like, and looks like.” Even if the water is technically safe to drink, that doesn’t solve the problem if people refuse to drink it because of the unpleasant salty taste, she says.

At the salinity levels seen in India’s groundwater, the researchers found, an electrodialysis system can provide fresh water for about half the energy required by a reverse-osmosis system. That means the solar panels and battery storage system can be half as big, more than offsetting the higher initial cost of the electrodialysis system itself.

How it works

Electrodialysis works by passing a stream of water between two electrodes with opposite charges. Because the salt dissolved in water consists of positive and negative ions, the electrodes pull the ions out of the water, Winter says, leaving fresher water at the center of the flow. A series of membranes separate the freshwater stream from increasingly salty ones.
Both electrodialysis and reverse osmosis require the use of membranes, but those in an electrodialysis system are exposed to lower pressures and can be cleared of salt buildup simply by reversing the electrical polarity. That means the expensive membranes should last much longer and require less maintenance, Winter says. In addition, electrodialysis systems recover a much higher percentage of the water — more than 90 percent, compared with about 40 to 60 percent from reverse-osmosis systems, a big advantage in areas where water is scarce.

Having carried out this analysis, Wright and Winter plan to put together a working prototype for field evaluations in India in January. While this approach was initially conceived for village-scale, self-contained systems, Winter says the same technology could also be useful for applications such as disaster relief, and for military use in remote locations.

Susan Amrose, a lecturer in civil and environmental engineering at the University of California at Berkeley who was not involved in this work, says, “This paper raises the bar for the level and type of scientific rigor applied to the complex, nuanced, and extremely important problems of development engineering. … Solar-ED isn’t a new technology, but it is novel to suggest developing it for systems in rural India, and even more novel to provide this level of detailed engineering and economic analysis to back up the suggestion.”

Amrose adds, “The water scarcity challenges facing India in the near future cannot be overstated. India has a huge population living on top of brackish water sources in regions that are water-scarce or about to become water-scarce. A solution with the potential to double recoverable water in an environment where water is becoming more precious by the day could have a huge impact.”

The research was funded by Jain Irrigation Systems, an Indian company that builds and installs solar-power systems, and sponsored by the Tata Center for Technology and Design at MIT.

More water treatment coverage here.


Greeley pursues $8 million bond project for sewer system improvements — The Greeley Tribune

April 26, 2015

sewerusa

From The Greeley Tribune (Trenton Sperry):

At its regular meeting this week, the council introduced an ordinance allowing the city to sell $7.5 million in bonds in May. The bond revenues would be used to fund improvements to the city’s sewer system, marking Greeley’s first issuance of sewer debt since 1994.

Greeley’s annual debt payments — estimated at $550,000 for the next 20 years — would be funded by current sewer user fees, according to the ordinance.

Victoria Runkle, Greeley’s finance director and assistant city manager, said rate increases for Greeley’s sewer customers may be on the horizon, but they would adhere to the city’s current rate schedule, which raises rates by about 2 percent to 3 percent each year.

“We assume we will have to raise rates over time,” Runkle said. “Will that actually come to pass? That will depend on if revenues continue as they are. There have been years when we didn’t raise rates.”

In a draft of the bond project’s official statement, the city claims Greeley’s single-family residential customers paid less for sewer services than 17 of 24 Front Range municipalities surveyed in fall 2014. However, the city will be required to raise rates, fees or charges to balance debt payments as needed.

The bonds are being considered to help Greeley make needed upgrades to the sewer system more quickly, Runkle said.

“We’re not earning enough interest on the money we have in cash funds,” she said. “Interest rates are very low. We’re only able to make about 2 percent on cash reserves, but construction costs are up to 4 or 5 percent.”

Portions of Greeley’s sewer system date to 1889, according to the ordinance, and about 4 percent of the current system is more than 100 years old.

More infrastructure coverage here.


The economic impact of water — and how technology can help — Denver Business Journal

March 24, 2015

waterdrop
From the Denver Business Journal (Jack Brewer):

Water is a valuable resource and we need to understand the financial reality of failing to address its importance.

Across the world there are examples of degraded water systems, and it is essential that innovations come to the forefront of this issue and present viable options to address this resource.

According to the World Health Organization, addressing both water supply and sanitation would bring about significant economic benefits. For every $1 invested in water supply and sanitation, there’s an economic return of between $3 and $34, depending on the region…

Promising technology

As we have seen in the cholera outbreak in Haiti and Malawi, and the Ebola outbreak in Sierra Leone, Guinea, and Liberia, we are witnessing examples of nations across the world that have had their infrastructures devastated by natural disasters and epidemics. These diseases are increasingly difficult to treat in the face of poor sanitation and a lack of adequate drinking water. Technology needs to step up to be able to provide this basic human right to nations in need.

One such technology that is making great strides in this effort is the patented Plasma Arc Flow technology by MagneGas Corp. While many of the major wastewater treatment plants take years to construct, MagneGas is a portable, easily operated technology that can be used to process these waste streams in a highly efficient manner.

The beautiful benefit of this technology is that the water becomes completely sterilized, and can then be brought back into the system for sanitation or irrigation needs. The other byproducts of this process are a fertilizer substance (if treating municipal waste) and a high-performance gas that can be used for heating or cooking.

Take time to reflect on what we stand to lose if we ignore the issue of improper treatment of the water we rely on. How we treat the water that we use has a direct impact on our personal health as well as the health of the entire ecosystem.

More water treatment coverage here.


9th Annual Grand Junction Water and Wastewater Conference, August 13 and 14, 2015

March 5, 2015
Grand Junction back in the day

Grand Junction back in the day

Save the Date!

August 13 and 14, 2015, are the dates for the 9th Annual Grand Junction Water and Wastewater Conference at the Two Rivers Convention Center, 159 Main Street, Grand Junction, CO. The Conference is designed to provide water and wastewater industry personnel with current information and training to address relevant issues in these industries.

Topics will include Water and Wastewater Treatment, Collection and Distribution Systems, Operations and Maintenance, Operator Math, Laboratory Practices, Safety Emerging Trends and Technologies. TU’s will be awarded.

Link: http://events.egov.com/eventreg/CO/event.htm?name=9thannualgrandjunctionwaterandwastewaterconference

More water treatment coverage here. More wastewater coverage here.


Water Values podcast: @OndaViaInc CEO Mark Peterman discusses water testing and technology advancements

February 20, 2015


A look at the art of water board governance from The Greeley Tribune #ColoradoRiver

February 15, 2015

Here’s an in-depth look at the Greeley Water and Sewer Board from Sherrie Peif writing for The Greeley Tribune. Click through to read the whole article and for the sidebar with the details about the current board along with some historic notes:

Most anyone who works closely with the water industry agrees the commodity is taken for granted by consumers, except for in a couple of instances.

“When water doesn’t come out of the faucet,” said Harold Evans with a laugh. “And when they get their bill.”

Evans, the chairman of the Greeley Water and Sewer Board, said it is unlikely that most know where their water comes from or how it gets to their faucets.

It is a complicated process involving more than a dozen lakes, ponds, rivers and reservoirs across Colorado. And in Greeley, seven men oversee it all.

It is so complicated, in fact, that fellow board member Robert Ruyle said it takes several years on the board before a member really understands it.

“Water board members serve 10-15 years before they really know what to do,” Ruyle said. “Even if they come to the board with water experience. Our system is unique, and it takes a while to understand it.”

It is also why, Evans said, the water board needs the absolute power it currently enjoys.

“The primary reason for establishing it this way was to provide for long-term needs in a non-political way,” Evans said.

Not everyone agrees, however, including a former top Greeley official who may take a proposal to the voters to put the power back into the hands of the Greeley City Council.

Many argue the Greeley water board has too much power, and its authority to set rates, development fees and the cost to bring raw water to a new development are all too high and there is no one that can reverse its decisions.

Members of the water board say what most don’t realize is how far ahead of the game Greeley is compared to other communities and water districts in northern Colorado.

And that — they say — is because of the way the Greeley Home Rule Charter is set up, giving board members the power to set rates and fees, acquire water and manage the system that cleans and transports it.

“When you think about what you pay for a cup of coffee, we supply a gallon of safe drinking water for four-tenths of one penny,” Evans said.

Board members all believe they are assuring many more generations to come plenty of the precious resource.

But has the original intention of Greeley’s forefathers outlived its usefulness?

Should voters change the way water has been managed for nearly six decades?

It all depends on who you ask.

WHICH WAY DID IT GO?

From as far away as Lake Granby on the Western Slope, into the Colorado-Big Thompson system, and eventually the South Platte River; or from as far away as Cameron Pass and the Poudre River, spring snow melt from the mountains flows through 500 miles of pipeline into two water treatment plants and into homes and business in Greeley.

It didn’t take long after Greeley was founded in 1869 for its forefathers to realize they needed to secure the rights to the water coming out of the mountains.

W.D. Farr, known to many as Mr. Water, and former Greeley Tribune publisher Charles Hansen are credited for bringing water from the Colorado River across the Continental Divide and to the Front Range. The Greeley water system is among the most elaborate and most rich in the nation, everyone close to the situation says.

Many say that’s thanks to the authority granted the Greeley Water Board when it was formed in the 1958 charter to manage the system.

Norman Dean, who was a member of the charter committee and one of those responsible for the Water Board’s authority, said it was a battle over who to put in charge.

“It was a very contentious subject,” Dean said. “Some guys wanted it to be a department of the city.”

But in the end, a University of Northern Colorado professor convinced the majority, including Dean, that it needed to be separate.

“Water and sewer generates a lot of money,” Dean said. “He did not want it to flow into the general fund for city council to use it as they wanted.”

Technically, it is a department of the city, but it is run by the water board.

The other option, said Leonard Wiest, former Greeley city manager who is now a consultant, would be to make the board an advisory board. Let them continue to do what they do, but leave the final decision to the Greeley City Council.

“We get a chance to vote on the city council,” Wiest said. “If we don’t like what they do, we can vote them out. The only thing the council can do right now to the water board is cut the budget. But they never do that either.”

The seven members of the water board are appointed by city council to serve a five-year term and cannot be recalled by voters. At the end of that term, they must be reappointed to serve again. However, no one can recall a time when the council did not reappoint someone.

“If at anytime they came to one of us and said, ‘We don’t think you’re doing your job,’ we would step down,” Evans said. “We may make decisions that some may not like, but we have to do what is best for the whole big picture.”

Additionally, there are no limits to the number of terms a water board member can serve. New members are recommended to the city council by the current board, leaving some to refer to it as a “good ol’ boys club.”

Many members have served for decades. Dean, who served 15 years on the board from 1989-1994, said that, too, was thought out by the charter committee.

“It seemed a shame to put term limits on them,” Dean said. “They finally get to understand it all and then they have to leave the board.”

The board controls a $26 million budget. Although city council ultimately has to approve any loans the water board requests, the water board has the authority to borrow money and sell bonds without going to voters, Wiest said.

“It’s taxation without representation,” Wiest said. “The water and sewer board is entirely independent. They do whatever they want.”

The board is responsible for setting water and sewer rates, plant investment fees (which are fees paid by a developer when a new home or business is constructed) and cash-in-lieu charges to get water to a new development.

Council can raise the rates and fees, but has no authority to lower the rates below a minimum formula set by the charter, which includes things such as depreciation and maintenance.

City Manager Roy Otto equates it to buying a car. You have to pay a minimum amount for a basic car, but all the bells and whistles are additional. If the water and sewer board wanted to raise the rates above what the formula says is needed to pay the bills, council could deny that.

“I have never since I’ve been city manager had a disagreement over the budget,” Otto said of the recommended budget versus what the council wants. “We all understand the importance of our rate structure. We have a sound system, I would put our system up against any in the area because the charter language considers depreciation and maintenance.”

Developers, however, have recently threatened to stop building in Greeley because development fees, especially for water and sewer, are too high, they say.

Many developers in the area have asked Wiest to lead an effort to ask voters to amend the Home Rule Charter in November, to make it an advisory board.

Wiest isn’t sure yet if he will, but he’s leaning toward leading the effort.

WHO PAYS THE WAY FOR GROWTH?

Greeley City Council has long charged its staff with the directive that growth pays its own way. In other words, fees should be charged to handle improvements or expansions when new developments come in.

Water and sewer is no different. New developments require the developer to supply the water rights to service the area, and new residential and commercial development must pay plant investment fees to help with maintenance and expansion to the system when it is needed because of growth.

However, the fees set by the water board are the source of disagreement.

At several recent meetings held by the city to discuss increased development fees that go in effect March 1, real estate brokers and contractors expressed concern that development was about to stop in Greeley because they can’t afford to build here compared to other communities. In particular, many believe the water and sewer fees charged against developers are too excessive.

Their contention is the increased fees drive up the cost of new homes in an area continuing to battle with poverty.

A recent attempt to lower those fees failed on a 4-3 city council vote. The argument against lowering the fees is that it puts the burden of paying for growth in the water system on the current users.

“It’s a philosophical belief,” Evans said. “Because on the other hand, you can say new development benefits everyone.”

Wiest said the water and sewer board are more concerned about someone who may move here in 50 years than they are those who live here now.

“The growth factor flies in our face,” Wiest said. “The person who moves here in 50 years will still have to bring their own water. But we are spending hundreds of thousands of dollars for water for the future.”

WHAT THE FUTURE HOLDS

Water board members say they are only trying to continue the logic of Farr, which has made Greeley the envy of many in Colorado for its long-term planning and vision in acquiring water rights.

“When you think about the previous boards and what they’ve done, we have the chance to stand on the shoulders of giants,” Evans said.

He added the land around northern Colorado is drying up, and people need to remember where they live.

“We are an arid landscape, but we want to look like the Midwest,” Evans said. “We have had water restrictions in place since 1905 for a reason.”

Ruyle agreed, adding it is getting more and more difficult every day to acquire water.

“It is a challenge to be able to acquire enough raw water to supply new growth for the city,” Ruyle said. “It is a limited resource in the area we live.”

In fact, 80 percent to 85 percent of the water used in Colorado is still used for agricultural purposes. That is a real challenge, both men said, because changing water use from ag to domestic in water court is a complicated process.

So what happens when Greeley’s economy moves away from agriculture? Evans asked.

“It is predicted we will have more than double our population by 2050,” Evans said. “Where is the water going to come from? What is it going to look like in 2050? Who knows? We’ll figure it out, but it’s going to look different.

“But we are fortunate to have the system we have. It allows us to do things others can’t do. When 2100 rolls around, I hope people look back on us and say, ‘Those guys in 2015 did a great job for us.’ ”

More Greeley coverage here.


Sterling: New RO water plant online and slowly winning over rate payers

February 6, 2015
Reverse Osmosis Water Plant

Reverse Osmosis Water Plant

From Radio Colorado College (Maeve Conran):

Coloradans pride themselves on the quality of their drinking water, most of which originates high up in the Rocky Mountains. But many communities on the Eastern plains have water that not only tastes bad, it’s out of compliance with federal drinking water standards.

Many diners at the J and L Cafe in downtown Sterling are sipping on glasses of tap water as they enjoy lunch on this December morning. That was not the case just a year ago.

“You couldn’t hardly drink it,” says Kathy Orchid, who says she never used to drink the tap water. “You could hardly drink it. It’s much better.”

The difference lies in the new multi-million dollar water treatment plant, less than a mile from the diner.

“The EPA…put the city on an enforcement order where we were basically told we had to fix the problem,” says Jeff Reeves, Sterling’s utilities superintendent, who supervises operations.

The city and the state had long been aware of problems with the drinking water, specifically that it contained radium and uranium, contaminants that can lead to kidney problems and bone cancer.

“All of these problems are naturally occurring,” says Ron Falco, who manages the Safe Drinking Water Program for the State of Colorado. “So this problem happens in the ground water as it’s moving through formations that may just have naturally high levels of radium or uranium.”

Falco says dozens of other communities, all on the Eastern Plains, are also struggling with water quality because like Sterling, they rely on ground water.

The EPA issued new drinking water standards in 2008, which meant those locations were now out of compliance with federal standards. Falco and other state health officials started working with the communities to improve the water systems.

“Historically, about 55 systems in the state of Colorado serving about 32000 people have struggled with uranium and radium in their drinking water,” says Falco. “By 2008, that number was at about 37 systems and about 21000 people.”

Sterling’s new water treatment plant is about a year old, and has put a dent in those numbers. This town of about 15,000 people in the South Platte River Basin was the largest municipality in the state facing this water quality issue.

The plant uses reverse osmosis to remove the uranium and radium. Reverse osmosis forces the water through a membrane, trapping contaminants which then form a concentrated brine.

But there are a couple of challenges. One is a 15% loss in usable water due to the treatment process, a significant figure for a region grappling with water quantity AND quality. The other problem is what to do with that wastewater.

Deep injection well

Deep injection well

Utilities manager Jeff Reeves says they’re storing that wastewater in an underground reservoir. “That’s down below an impermeable layer so it can’t get back up into the drinking water.”

Despite those two challenges, Reeves says the city of Sterling now has water that is well within federal standards. In addition, the reverse osmosis process has also improved the taste.

“We thought that we might as well make the water much more aesthetically pleasing,” says Reeves. “If you’re going to produce a product that people are going to have to pay for it’s a lot easier to get along with the customers if the water is good.”

More water treatment coverage here.


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