Overview: With only 3% of the planets water being fresh, the ongoing California drought has brought the finite nature of fresh water resources into clear focus.
Furthermore, two thirds of this water is locked up in Glaciers, mostly inaccessible for human use. Two things appear certain: (1) Water will be more expensive in the near future, and (2) additional government regulation of large consumers of fresh water is inevitable. As large users of fresh water, Commercial Pools are likely to be a target.
The major factors affecting water use at a commercial pool are evaporation; backwashing; chemical re-balancing, leaks and occupancy (the number of users). As an important first step, commercial pool operators need to at least track their water consumption. Typically, what can be measured can be improved. It turns out that all kinds of information can be derived from continuous data logging of water use. For example, leaks can be detected, use of covers at night can be monitored and backwashing frequency and duration can be tracked. Fortunately, The MKT Aquatic Brain Smart Pool Monitor/Control system has recently been updated to include water consumption data logging and pool chemistry monitoring. The energy saving features of the Aquatic Brain Controller/Monitor can easily pay for the costs of installing such a system which now brings the important benefit of water use tracking.
One clear opportunity for water conservation is the possible recycling of the water used to backwash the pool filter system. The frequency of backwashing, which clears the (typically sand) filters of debris and other contaminants, varies widely, but heavily used pools may be backwashing as often as once a day during peak (typically summer) season. Each time this technique is employed, between 1500 and 4,000 gallons of water is dumped into the local sanitary sewer. This represents a clear opportunity for onsite recycling. This may in fact be the only option short of pool closure or severe curtailment of operating hours for those trying to comply with severe water cutbacks, like those with 25% mandatory water cutbacks in California.
“Water Smart Pool Water Recycling System”
The functionality of the aquatic brain
How it works:
By contentiously monitoring the flow and pressure differential across the inlet and outlet of the filter bank, the system determine the appropriate time to backwash the filters. This step is designed to reduce over back wash and keep the water quality as peak health to comply with health department requirements.
Using an appropriate amount of on-site storage to hold and treat back-wash water, the system can save 95% of this water (and associated chemicals) which is typically dumped down the drain. The back-wash water goes into Tank #1 first where solids settle in the bottom where they can easily be flushed out with a small fraction of the total gallons of backwash.
During the actual backwashing, the pool water level is replenished from Tank #2, which contains recycled water from prior backwashes, supplemented as necessary with fresh water from the local utility. As a further safeguard, this recycled water is passed through a UV sanitizing device before going to the pool. After the settling in Tank #1 has occurred, 95% of the (to be) recycled water is pumped to fill the now partially depleted Tank #2. Then the drain port on Tank #1 is opened briefly to flush out the remaining water and concentrated solids, readying the system for the next backwash.
Water Savings potential
Ideally, a commercial pool supposed to back wash it volume worth annually. With over 3,000 commercial pools in California with average volume of 650,000 gal, there are 2 trillion gallons of fresh water wasted annually.
There are 3 types of commercial pools:
- Municipal pools – typically municipal pools backwash daily an average of 3,000 gal, which translate to 1,000,000 gal/ annually. With 1,000 municipal pools in California. This translates to 1 trillion gallons of water wasted annually. With water cost at $.03/ gal, using the proposed solution would save the average municipal pool $30,000 annually, additional savings in various chemicals and sewer disposal cost.
- YMCA type pools – typically these pools would back wash 4 times / week and average of 3,000 gal, which translate to 625,000 gal annually. With estimated 1,000 commercial pools in California, this portion is representative of 625,000,000 gallons of water wasted annually. Switching to the Aquatic Brain would not only save a customer of the Aquatic Brain, on average, $18,000 annually, but additional savings would be found in the costs of various chemicals and sewer disposal.
- Olympic size commercial pools – typically these pools would back wash 1 times / week and average of 3,000 gal, which translate to 156,000 gal annually. With estimated 1,000 commercial pools in California. This translates to 56,000,000 gallons of water wasted annually. The annual savings these pools would be $5,000 in water savings, additional savings in various chemicals and sewer disposal cost.
The constant monitoring prevents prolonged backwash and provides alarms to customers when the backwash uses more than its allowance. This helps prevent accidents where equipment malfunction allow hundreds of thousands of gallons of water to flush into the sewer system.