Yes, the system is installed with a "belt and suspenders" approach to protect the water supply. The system will have backflow prevention per code at the inlet from the water main. The water will then circulate through a heat exchanger which isolates the building loop water from the municipal water. Backflow prevention will be installed once again and at the insertion point before returning to the treatment facility. In addition, each heat pump will have one-way flow valves that provide positive protection from backflow. Any potential contamination is eliminated in the treatment process.

The piping design will be no different than a normal potable water system. The locally accepted pumbing standards will be followed by the mechanical engineer. This should be an integral part of any installation specifications.

Large temperature excursions can occur if a system is short-circuited excessively. There are several ways to avoid the problem. One possible solution to the short-circuiting issue is to map the location of the treatment plants, direction of flow, size of mains as well water line location on the grid. Without question one must be cognizant of where the supply and return lines will be located. Our engineers will work with the utility to provide a safe set of performance specifications.

Changes in water temperature are an important factor. A crucial element of approving a water+ installation is to assure there is adequate water supply to absorb the temperature differences. The water+ system restricts the change in temperature of water as it flows through the heat pump to no more than 5 degrees F.

Once the water leaves the unit, water mains, and ground surrounding the mains and the dilution effect due to volume and usage, will absorb the temperature difference. Assuring that the water mains will absorb or reject the required heat is the key to the design of the system.

Water temperature within most municipal water systems fluctuates by far more than 5 degrees. Water pumped from wells or surface water can be 20 degrees cooler or warmer than water in the mains. Water held in storage tanks or water towers on very warm or cold days could fluctuate from 39 degrees to 79 degrees. The 5-degree change caused by the water+ system will not deplete the chlorine level or cause corrosion in the heat pump heat exchanger.

For bacteria to grow it needs three things: food, temperature, and time. The water+ system does not provide any of these. Our system is not introducing any potential food for the bacteria. The fastest growing bacteria needs 20 minutes at 98.6°F and must have food. And our system moves at speeds as high as 1,000 GPM. In every case, we are temporarily raising or lowering the water temperature, which prevents bacteria growth. We contended that by keeping the water agitated, we are maintaining the water quality. Furthermore, if there were any question, the monitoring/treatment station will retreat the water before reinsertion.

We feel that if the system is designed correctly, most of the water temperature change will be lost through usage. You have to consider the US uses 800,000,000,000 gallons of water on any given day. Certainly this will not be a problem in the early stages. In fact, it will likely be a few years before that becomes an issue. Remember, water heating produces system cooling; air-conditioning produces system heating. The accumulated impact is not as great as individual applications. When and if this becomes an issue, the water utility will need to make a business decision: keep growing or back off from expanding the system.

We do not recommend double wall heat exchangers to be used in conjunction with the water+ system. The only installations currently using double wall heat exchanges are the direct return systems. They reduce operating efficiency enough to put added load on the water plant. It is an option but should be a last resort due to the increased cost and reduce efficiency.

A typical water+ system has two completely separate loops: the municipal water loop and the building loop. Ninety-nine percent of the time if a heat exchanger fails, both fluids would leak to the floor, indicating the need for repair. In the extremely rare event of a breach, the building loop is designed to run at a much lower operating pressure than the municipal water loop. The breach would cause the building loop to over pressurize. A pressure relief value would immediately open allowing the building loop water to dump down the sanitary sewer and once again indicating the need for repair. The heat exchangers used in this system are designed to handle over 400 PSI. Most water systems operate at much lower pressures, 40-70 PSI. It is conceivable that several ounces of mineral oil could get into the water stream. In addition, there can be some freon entry. The mineral oil is of low volume, while not certified as food grade, it is relatively safe. The freon is one of advanced materials and will outgas leaving no residue.

No. The return directly from first sites installed was the choice of economy. In addition, the state of Oklahoma currently prefers a full time attendant on duty at each such sub-station. This is expected to change although the specific Comanche site may not change due to economics.

Several points should be considered. Perhaps the cost for a line returning water to the finishing plant is prohibitive. On the other hand, the utility may actually need some storage in outlying areas due to system growth. We work with each utility to determine the best approach. The utility decision is the final determinant.

Yes! Actually, with modern monitoring technology permitting remote review of performance, many water utilities are seriously looking at remote facilities to reduce the strain on central distribution centers. If cost is the issue, water+ will cover the sub-station cost to allow no out of-pocket expense to water utilities.

The best range is 45-90 degrees F (7-32 degrees C). Well systems are inherently best due simply to their very stable temperatures. Surface water is still fine. Where temperatures are too low, we use additional technologies.

They work well. Our engineers work with the utility to offer the best and safest finished model.

We will run an economic proforma to make that determination. In almost all cases, the answer is yes. Generally, the water utility has no risk since initial cost is covered by water+.

This is a city management question. The water utility generally retains the profit.

About $0.08 per thousand gallons pumped. This would include the extra maintenance, electrical and pump amortization. This figure has proven to be reliable with all facilities checked to within 15%. The additional pumping is paid by the customer.

Unfortunately this is an issue. Very specific language should be used in the design guide. All pipes should be clearly identified. For total asuranace, the water purveyor can meter the supply and return lines. It is not cost prohibitive to meter each site, and water+ offers the option of billing by metered water use. Water utilities deal with this issue everyday.

As might be expected, the response is all over the board. We have met with extremely favorable response. Connecting geothermal heat pumps to the water system is not a new technology. The water+ system is the new and improved way to connect and return water to the municipal water main due to the addition of the treatment/monitoring station. We are working to set up small (up to a few hundred tons) systems as test beds in some states. Certainly the integrity of the potable water supply is primary. Also, it is best if state level regulators have a good understanding of the system. This is best accomplished by keeping them involved at the early stages. We have included backup data for systems that have been in operation for up to 10 years.

There are several ways to approach the state. First and foremost have a project or customer. The best customer for a first installation is a state, city or federally owned building. Schools and military installations are some of the best.

Second, pick a potential location and have a potential design already complete. Do your homework so that any potential questions can be answered at the meeting. Some of the basics include, main size, water flow, location of large users, and location of treatment facility.

Third, start at the highest level and work your way down. If you contact the water department initially, chances are your will get the easy answer, NO. In some cases this decision can be made at the local level.

Generally we recommend working with states at the very earliest stage. There should be a specific project in mind before making the first contacts. Water+ will assist with state approvals.