Attention Policy Makers:

Many municipalities are faced with new challenges in managing their water supplies. Among these problems is the issue of salinity control. Along with meeting National Pollution Discharge Elimination System permit requirements for their waste water treatment facilities, salinity management also plays a vital role in ensuring the reliability and future usefulness of the water supply in general.

Water SalinitySalt is difficult and very expensive to remove from waste water and so salinity control poses challenges both intellectually (how do we control it?) and financially (once we decide how to control salt, how do we pay for it?). As more and more waste water is cleaned and reused to meet rising demand, this emphasis on salt control will only increase.

The accepted methods of removing salt from waste water are also very energy and water intensive. They take a lot of power to operate and in the end lose as much as 25% of all of the water that they process. This “lost” water, concentrated with the salts and other impurities that are removed, is essentially gone forever.

Many municipalities have used reclaimed waste water for limited irrigation purposes for years. It is the least expensive way to reuse waste water because some elevated salt levels are tolerable for many irrigators. It is attractive precisely for this reason as minimal salt reduction is required. These projects are often referred to as “purple pipe” non-potable reuse programs. The thinking is that any waste water that can be reused for parks, golf courses or freeway landscape irrigation is less water required from the general drinking water supply. It helps, but in the long term is not adequate to solve the salt problem.

Reclamation for potable uses is now necessary to ensure an adequate water supply. In some areas potable reuse waste water reclamation is already being done. The Irvine Ranch Water District in Orange County, CA is reclaiming 20M gallons of waste water per day, using advanced RO technology, and using that water to recharge the local aquifer (ground water storage). Ironically, this facility was first conceived, approved and built to control sea water intrusion. Years of ground water pumping had resulted in sea water flowing further and further inland. The reclaimed fresh water is intended to “push” this encroaching sea water back out of the aquifer. The result however is that water that was sewage is being reclaimed for drinking and other domestic uses.

Another California City, after implementing numerous source control programs, has decided that the only way that they can meet the requirements of their NPDES permit for chloride (100 mg/L), is to build an advanced reverse osmosis plant for the purpose of reducing salt in the water they discharge. This step will be taken not for re-use by the City, but so that the waste water they discharge to a local river will contain salt at a level that complies with their waste water permit. There is no other benefit to the City or its residents.

The cost to reduce waste water salt for this City is conservatively estimated at $250M in capital construction expense. It is also estimated that it will cost as much as $20M per year in ongoing energy costs (estimated at $1M per month), labor and other consumables to keep it operational.


Figuring for inflation it will cost this city, of approximately 250K people, over $1B over the next 20 years, just to reduce salt in their sewage! It will be paid for with borrowed funds (in the form of federal and municipal bonds). These borrowed funds will be repaid by adding $690 dollars per year to every property tax bill in the city, forever. It is estimated that the initial investment will take decades to repay and that is putting nothing aside to cover the annual operational costs. Perhaps most ironic is the fact that the salt that they must remove is not even salt that they added to the water. It was already there.

Needless to say the costs of managing salinity, using currently accepted methods, are high. They consume energy and water and are really only marginally effective. The need for such treatment is also growing and will continue to grow. Over time the benefits of this kind of treatment will diminish, requiring larger and larger systems, so the costs to install and operate them will also continually rise.

The Puroserve system represents another way to look at salinity management. An approach that would require little or no municipal capital investment and utilizes 100% of the water it processes. Puroserve also addresses the primary source of waste water salinity that the municipal approach cannot possibly address – TAP WATER SALT.

Tap water salt is in fact the real problem in salinity management. Ever increasing tap water salt is the one source that has proven impossible to address using source control or the municipal waste water treatment model. Puroserve addresses tap water salt, by far the biggest “source”, while transferring literally 100% of the cost to a customer who is actually happy to pay for it because of the benefits that they will receive.

By using advanced, low energy RO technology at a different point, where it is easier to apply and easier to pay for, enormous cost and efficiency improvements would also be realized. It would require no additional energy and it would waste no water? All while delivering a better overall salinity management result AND delivering immediate benefit for the people who are paying for it, local residents and businesses.

Puroserve applies RO upstream of the water user (at customer homes), to improve tap water. When used in this way Reverse Osmosis is not only easier to apply, it is far more efficient and can do far more good for everyone. It will improve the household water for the homeowner who is using it (so they benefit from better cleaner water), and it will also discharge waste water from the home that is much easier to reclaim because the tap water salts, by far the biggest source, have been removed.
Puroserve systems, installed in sufficient numbers, would help manage the problem of environmental salinity more effectively and at a much more reasonable cost while also reducing water waste.

This is true for several reasons including.

  • By far the biggest source of salt in waste water is the salt that is already in the tap water. This is a source of salt that municipal waste water RO treatment technology can never address.
  • Areas that are salt sensitive also tend to have the worst tap water. That is why there are a disproportionate number of salt water softeners in these communities.
  • Treating tap water with RO is far easier than treating waste water requiring–
  • Less Pressure – operating using the pressure provided in the line by the city.
  • Less Energy – line pressure means no additional energy is required.
  • No wasted water – all waste water or concentrate is used to provide irrigation water onsite. Each installation becomes a miniature waste water salinity plant.
  • Cleaner municipal waste, that is lower in salts, is far easier (ie. less expensive) for waste water authorities to reclaim.

Puroserve is a revolutionary idea. It is much more than a household water system. It does improve household water to a degree that has never been achieved before. It not only softens it also purifies, addressing contaminants that no other technology can control, so it makes our customers very happy. That was our goal actually. But we have come to view it differently. We realize now that it benefits all of us. It actually turns each home that uses it into a mini water treatment plant while it wastes nothing.

For more information contact us.