Murky water explained –
Questions have come up about the condition of the lakes.
Why are the lakes so murky?
Is the reclaimed water responsible for this?
Why is there an algae bloom on #17 and what can be done about it?
Prior to December 6, the water being pumped into the lakes at #12 on the Championship and #5 on the Challenge Course was untreated canal water from the Colorado River. The canal water is untreated, as in no filtering is being done so it is carrying a lot of silt. This is why the lakes had become so murky. Since December 6, we have been getting reclaimed water from the Palm Desert Sewage Treatment plants so the murkiness has not gotten any worse.
Interesting to note that all of the irrigation water for both courses are coming from only those two lakes, #12 and #5. The other 20 lakes have been filled in the past with “well” water and only receive water from the two lakes as needed to maintain certain levels. The pipes to these lakes from the two lakes are set roughly a foot and half above the bottoms so consequently the silt has a chance to settle some before being pumped out. Therefore the water is not nearly as silty.
Bryan wants us to know that they will be focusing on controlling odor and algae blooms going forward. There will no longer be an attempt to “clear” them up. The clearer they are the more likely a bloom will occur. A combination of a dark dye and Copper sulfate is being carefully added to combat the bloom.
In all, the maintenance of the lakes is a constant challenge because of the variations in temperatures, bright sunshine, bird droppings, fertilizer, dirty canal water and golf balls. Yes, golf balls. The golf balls are sometimes a challenge because they can get through weak areas in the strainer baskets. The pressure of them in the weak areas causes the basket to give way and the balls get pulled into the pump impeller. The impellers are made of brass which is a soft metal.
Reclaimed water explained by Olivia Bennett, the Nonpotable Water Operations Manager:
“The treatment plants are highly regulated by the State and abide by a regulatory discharge permit in order to safely provide recycled water for golf course and landscape irrigation to our customers. The State of California has approved of over 40 uses of tertiary disinfected recycled water. Full body contact, snow making, fire-fighting, growing crops, decorative water fountains, laundries, car washing, construction, cemeteries, school yards, groundwater recharge, residential landscape irrigation and golf course irrigation are just a few of these approved uses. Please find the attached document listing the approved uses for tertiary disinfected recycled water.
The use of recycled water is endorsed by:
Department of Health Services
State Water Resources Control Board
Department of Water Resources
County Environmental Health Directors
U. S. Bureau of Reclamation
U. S. Environmental Protection Agency
Task Force Appointed by CA Legislature
California Medical Association
Tertiary disinfected recycled water is the result of a state of the art multi-step treatment process. In the first step, a mechanical bar screen removes large inorganic and organic debris that may have entered the collection system. Also in this first step grit sedimentation tanks remove grit and sand. The secondary processing step includes aeration and clarification tanks where microorganisms digest the remaining organics in the water. The sludge from this step settles out, is removed and sent to a belt press to be processed as biosolids and is transported to composting facilities in Arizona to be used as fertilizer. The water remaining in the clarifier is referred to as secondary effluent. The third step or tertiary treatment process coagulates remaining particles in the effluent and sends the effluent through a large filter of anthracite coal, sand and gravel to remove these particles. From the filter, the water is sent to a chlorine contact channel where it is chlorinated for at least 90 minutes to kill any residual bacteria, etc. When the process is completed the tertiary disinfected recycled water meets the state water quality and public health requirements in order to be allowed to be provided for golf course and landscape irrigation. Samples are collected continuously 24/7, daily, weekly, monthly, quarterly and annually to prove that these requirements are met.
Tertiary disinfected recycled water is one treatment step away from becoming an allowable source of drinking water. Because CVWD’s treatment plants are not equipped with the nano-filtration, micro-filtration, ultra-violet, and/or other additional treatment processes to complete this final treatment step it is considered nonpotable water. In order to be considered a potable water source, the State must deem it as a potable water source. The Coachella Valley has a large aquifer that provides our potable water. Although recycled water is being treated to potable water in Orange County and other areas of California are considering it, CVWD has not determined it to be feasible or necessary, at this time, to invest money in our treatment plants to treat recycled water to be a potable water source, especially when there are 121 golf courses within the valley needing only a nonpotable water source for irrigation.
Using recycled water in lieu of precious groundwater helps reduce overdraft of our aquifer and allows for a sustainable drinking water supply for future generations. Source substitution and in-lieu recharge using nonpotable water for nonpotable purposes is a major component of the Coachella Valley Water Management Plan. By using nonpotable water for golf course and landscape irrigation, Palm Valley Country Club is a part of the sustainable water supply solution for the Coachella Valley.
Tertiary disinfected recycled water is so clean and clear that it is hard to visibly tell the difference between it and domestic drinking water, thus the recycled water must be distributed in purple pipe and signage must be visible to the public where recycled water is discharged. Purple is the State approved color for recycled water appurtenances.”