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.


Southern Delivery System: Jury awards rancher $4.6M — The Pueblo Chieftain

April 28, 2015
Southern Delivery System route map -- Graphic / Reclamation

Southern Delivery System route map — Graphic / Reclamation

From The Pueblo Chieftain (Chris Woodka):

A Pueblo jury late Thursday awarded rancher Gary Walker a $4.6 million judgment against Colorado Springs Utilities for the Southern Delivery System pipeline crossing Walker Ranches in Northern Pueblo County.

Walker contends the amount is far short of what the pipeline has cost him. During the trial, he contended that the conditions of the SDS easement have jeopardized a $25 million conservation easement he was negotiating with the Nature Conservation for $1,680 an acre on 15,000 acres.

Walker said the conditions of the utility easement through his property allow for access that negates the value of the conservation easement, and that soils from offsite that were used as fill are contaminated with seeds from invasive species. Rain storms already have caused erosion on the pipeline scar and the damage could be greater in the future.

He also said he is fearful that Colorado Springs will take action against him if normal ranch activities interfere with the SDS permanent easement that is 100 feet wide across 5.5 miles of Walker Ranches.

The jury awarded Walker $4.665 million in damages in addition to the $82,900 actual value of the easement. The actual value was part of Judge Jill Mattoon’s instructions to the jury.

“We stung Colorado Springs, but it will do little to protect the next little guy or rare environmental landscape that gets in their way,” Walker said in a written statement provided to The Pueblo Chieftain. “My attorneys were amazed at CSU’s response against one rancher. It was like using a tank to kill a fly.”

The rancher charged that Colorado Springs drove up litigation costs intentionally. In December, Walker won a Pueblo District Court decision on costs of about $500,000 to that point, but the state Supreme Court pushed the decision back until the trial concluded. In that case, Walker said Colorado Springs had needlessly delayed trial.

“Colorado Springs punished us a great deal both financially and emotionally but I am glad we did it and I would do it again even though we lost a lot more than we gained,” Walker said. “Our financial loss is minor when compared to the loss of another open space and protected wildlife habitat area.”

Walker plans to raise the issue of how he was treated by Colorado Springs to Pueblo County commissioners, who issued a 1041 permit for SDS in 2009.

“My hope is that Pueblo County stands their ground and protects everyone by holding the city of Colorado Springs and their utility company to the terms of the 1041 contract they signed in 2009,” Walker said.

Walker also indicated that he is nervous about whether he will actually be able to collect the $4.6 million, since he expects Colorado Springs to appeal.

Colorado Springs has not indicated if it will ap- peal the judgment.

“We are disappointed in the outcome and will be exploring our options to protect the interests of those residents who are helping to fund the SDS project and will be impacted by this outcome,” said Janet Rummel, SDS spokeswoman for Colorado Springs Utilities. “We do not believe the result was supported by the evidence presented.”

She contended that Colorado Springs has worked to address Walker’s concerns and to offer fair compensation for the easements, along with paying $720,000 to relocate cattle during construction.

“We will continue to work with Mr. Walker and all easement holders on the SDS alignment to complete successful restoration and revegetation, as well as to responsibly maintain the condition of our easements,” Rummel said.

More Southern Delivery System coverage here.


Fountain Creek District meeting recap

April 28, 2015
Fountain Creek Watershed

Fountain Creek Watershed

From The Pueblo Chieftain (Chris Woodka):

A debate over water quality on Fountain Creek in Pueblo County bubbled over into last week’s meeting of a district formed to improve Fountain Creek.

Pueblo Wastewater Director Gene Michael told the Fountain Creek Watershed Flood Control and Greenway District that studies by the city show no clear link between increased development and increased amounts of selenium in the water supply.

He said information from some city studies was misinterpreted at a recent function of the Arkansas River Basin Water Forum and he wanted to clear the air for the Fountain Creek district.

“There’s no way to measure what the selenium was 100 years ago,” Michael said. He explained there simply was no technology to measure parts per billion at the time. “The levels in 1981, when it was first measured, were higher than today.”

Selenium is known to accumulate in the Pueblo area because of water flowing over the Pierre shale formations.

The arguments are crucial to a case Pueblo is trying to make with the Colorado Water Quality Control Commission that it should have a specific discharge variance. An April hearing on the issue was postponed.

Pueblo maintains that it removes some selenium from groundwater intercepted in its treatment plant under a temporary modification. The ambient concentration of selenium in Fountain Creek and the Arkansas River near Pueblo is more than three times the EPA’s numeric standard, 4.6 parts per billion, he said.

The discussion touched a political nerve with the Pueblo city and county representatives on the Fountain Creek board.

“This is an interesting discussion to have with the Water Quality Commission,” said County Commissioner Terry Hart. The commissioners have supported a numeric standard on Fountain Creek, largely because of dealings with Colorado Springs Utilities for increased releases related to the Southern Delivery System. “My feeling is that we study it, find out where it is coming from and take it out.”

“It’s important to discuss it,” said City Councilman Dennis Flores, who invited Michael to speak at Friday’s meeting. He noted that the Pueblo Area Council of Governments supported the city of Pueblo 9-2, with two county commissioners in opposition. “I feel strongly about this and think it’s important.”

More Fountain Creek watershed coverage here.


New Study Links Weather Extremes to Global Warming — @WillSarni

April 28, 2015


“Whitewater park features are not suitable fish habitat” — Jim White

April 28, 2015
Durango whitewater park plans

Durango whitewater park plans

From The Durango Herald (Mary Shinn):

Whitewater advocates have anecdotally noticed more fishermen near whitewater rapids, and they are working on gathering data to show how the parks can benefit fish.

But Colorado Parks and Wildlife data show the parks degrade fish habitat and their ability to migrate upstream, said Jim White, a biologist with the department.

“Whitewater park features are not suitable fish habitat,” he said.

Human-made parks create fierce velocities that make it hard for fish to migrate over them. Fish must also battle a washing-machine effect in the human-made pools, he said.

The parks are also being built in or near towns, where whitewater rapids would be less likely to occur.

“By the time you get down to broader valleys … they are not typically natural features,” he said.

However, engineers and advocates – including Scott Shipley who designed the improvements to Smelter Rapid – argue whitewater parks can be built to improve fish habitat, and Colorado Parks and Wildlife is basing its conclusion on limited studies.

“As far as hard science goes, there is very little hard science on the issue,” said Shane Sigle, with Riverwise Engineering.

Despite the disagreement, proponents on both sides are interested in compromises that help protect fish. Some 30 whitewater parks are operating across the state, and they are boosting tourism and driving local economies, according to professionals in the field.

Smelter Rapid in Durango is an example of such a compromise. It was not quality-fish habitat to begin with, so it made sense to build permanent structures in that section, White said.

Colorado Parks and Wildlife also supported the Whitewater Park, saying construction of the permanent features secured a recreational-water right that helps protect fish from low flows, he said.

The city already was maintaining Smelter Rapid for whitewater features prior to construction of the park. The Army Corps of Engineers anticipates the grouted structures will limit the disturbance from continued maintenance, said Kara Hellige, senior project manager for the corps.

In addition, the corps requires the city to monitor the stability of the structures and banks, water quality and the movement of sediment after construction.

The monitoring required at Smelter Rapid and other parks should help engineers better understand how human-made rapids impact rivers.

More whitewater coverage here.


‘Split season’ approach to water use could benefit state’s rivers, including the Crystal River — Aspen Journalism

April 28, 2015

littlecimarronriver2022cwt
From Aspen Journalism (Brent Gardner-Smith):

An innovative deal put together by the Colorado Water Trust to leave more water in the Little Cimarron River, a heavily-diverted tributary of the Cimarron and Gunnison rivers east of Montrose, could serve as model solution to the low flows that often plague the Crystal River in late summer.

“Any new tool coming online that can help agriculture and the environment share water could be useful in the ongoing conversation about the Crystal River,” said Amy Beatie, the executive director of the Colorado Water Trust, a nonprofit dedicated to restoring streamflows in Colorado.

The “new tool” is a recognition that under current state law an irrigation water right can be changed to also include a late-season instream flow right, at least if the Colorado Water Conservation Board has an interest in the water right.

Under such a “split season” approach, water can be diverted as normal to, say, grow hay in June and July. But in August and September, when river levels typically drop, water normally diverted for irrigation can be left in the river.

In the case of the Little Cimarron River, it will allow 5.8 cubic feet per second of water to flow past a diversion headgate in late summer down nine miles of river, including 3.3 miles of the Little Cimarron normally left nearly dry.

Rick Lafaro, the executive director of the Roaring Fork Conservancy, which is working to find solutions to low flows on the Crystal River, said he thought the Little Cimarron deal was “pretty exciting.”

And Beatie of the Water Trust said the concept has statewide application.

“If there is anybody who would be willing to forgo irrigation later in the irrigation season, and would be interested in a payment from us to do that, and then would allow us to take a water right through the water court process in order to protect it for instream flow, then it works anywhere in Colorado,” Beatie said.

But such arrangements can be complex.

“These water acquisitions all require a confluence of a lot of variables,” said Linda Bassi, the head of the CWCB’s instream flow program. “You have to find a water right that is available, and it has to be in a place where it will benefit a reach that needs water.”

ranchpropertylittlecimmaronrivercwcb

ranchalonglittlecimarronrivercwt

Streams dry from diversions

Sections of the lower Crystal River often run dry, or nearly so, in the late summer months, due in large part to a number of irrigation diversions on the river.

A similar situation has existed for years on the Little Cimarron River. It flows pristinely out of the Uncompahgre Wilderness but is often left nearly dry below the McKinley irrigation ditch.

In an effort to leave more water in the Little Cimarron below the McKinley Ditch, the Water Trust signed a contract on April 23 with the CWCB that allows for 5.8 cfs of water to be left in the stream in late summer.

“As a result, the Little Cimarron River is expected to remain a live stream during the irrigation season, and no longer experience dry-up conditions below headgates,” a memo prepared for the CWCB’s September 2014 board meeting states.

The memo also notes that the “split season use of the water is distinctive because it acknowledges and preserves the value of irrigated agriculture as well as the value of restoring flow to a local river.”

The water left in the Little Cimarron will also benefit a reach of the main Cimarron River, which runs into the Gunnison River below Morrow Point Reservoir.

littlecimarronrivervicinitymapcwcb

Deal took years

The Colorado Water Trust has been working on the deal since 2008, when John Shephardson contacted the Trust about buying his water rights.

Shephardson had subdivided his scenic 214-acre ranch along the Little Cimarron into 35-acre parcels and wanted sell the land and the associated water rights.

Shephardson owned 1.5 shares, or 18.75 percent, of the shares in the McKinley Ditch. His shares gave him the right to use 5.8 cfs of water to irrigate 194.5 acres of land, where he grew hay and raised cattle.

The McKinley Ditch as a whole has rights, with appropriation dates ranging from 1886 to 1912, to divert up to 31 cfs of water from the Little Cimarron to irrigate 947 acres of land.

Shephardson was ultimately not successful in developing his property and Montrose Bank foreclosed on it.

In 2012 Western Rivers Conservancy, which buys land to help preserve rivers, purchased both the property and the water rights from Montrose Bank.

In January 2014 the Water Trust bought the 5.8 cfs of water rights from the Conservancy for $500,000.

In September 2014 the CWCB board agreed to purchase a permanent “grant of flow restoration use” from the Water Trust for $145,640. The CWCB is the only entity under state law that can hold an instream flow right.

The state’s purchase price was based on an estimate of the loss of agricultural revenues that would come by leaving the water in the river in late summer.

“We’re purchasing a right to use the water that would have been used to produce a second cutting of hay,” said the CWCB’s Bassi.

littlecimarronrivercwt

The water court process

On Dec. 31, 2014 the CWCB and the Water Trust filed an application in Div. 4 Water Court in Montrose to change their water rights on the McKinley Ditch to add an instream flow right.

To date, only two statements of opposition have been filed in the water court case, and both are from neighboring landowners (David Taylor, Wayne Mauer) making sure their water rights are not injured by the change of use, said Beatie of the Water Trust, who believes the water court process will go smoothly.

Beatie said no part of Colorado water law needs to be changed to make the deal happen.

“All we’re doing is transferring a water right to instream flow purposes and making sure in our application that there isn’t injury to other water users,” Beatie said. “We took a customary transfer process and applied it to the outcome that we wanted, which was partial irrigation and partial flow restoration.”

Bassi, of the CWCB, said that creating a “split-season” use of water for both irrigation and instream flow has long been possible under Colorado water law, but such a use just hasn’t been applied for until now.

“This is the first time we’ve done it and we’re hoping it will create a template for more partnerships with agriculture and environmental interests,” Bassi said.

James Eklund, director of the CWCB, says the effort on the Little Cimarron is evidence of a “mindset shift” he’s seeing among irrigators, environmentalists and water regulators in the state.

“The idea that you can use a split-season concept exemplifies the potential for people to get over the perception that a water right can only be used for one thing,” Eklund said. “It is representative of a very big change that I think we’re going to need to see more and more of going forward.”

Editor’s note: Aspen Journalism is collaborating with The Aspen Times and the Glenwood Springs Post Independent on coverage of water and rivers. The Times published this story on Monday, April 27, 2014.

More instream flow coverage here.


The latest newsletter from the Water Center at CMU is hot off the presses #ColoradoRiver

April 27, 2015

Colorado River Basin

Colorado River Basin


Click here to read the newsletter. Here’s an excerpt:

POWELL INFLOWS LOW, RELEASES UP
A low snowpack across the Upper Colorado River Basin has led to projections of below-average inflows into Lake Powell, but management guidelines indicate releases from Powell of at least 8.23 million acre feet, back up from last year’s historically low 7.48 million acre foot release. The most recent Bureau of Reclamation discussion of current data, projections & operations can be found here.


Follow

Get every new post delivered to your Inbox.

Join 1,181 other followers

%d bloggers like this: