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The vessels are at the heart of the reverse treatment process. For every four gallons of treated, three gallons of usable water is produced. USING REVERSE OSMOSIS TO MAIm WATER The reverse osmosis process can turn brackish water into a valuable resource for golf courses. by GLEN A. MILLER

ATER is perhaps the most osmosis (or "RO") water treatment tions to achieve the same concentra- precious resource for any process. tion. To do this, water from the fresh W golf course, and a reliable, side would pass to the salty side and economical supply of good quality irri- What is Reverse Osmosis? this would continue until they reached gation water should be a priority for To understand reverse osmosis, one an equilibrium. At the end, the water every course. What is the water situ- must first understand osmosis. Osmosis level on the original salty side will be ation at your course? Are you buying is a naturally occurring phenomenon higher (and now less salty), and this your irrigation water, and is the cost of that is all around us. The cells in your water height difference is called the water becoming a real budget issue? body get water via osmosis. Osmosis is . Do you have to curtail watering due to the process by which water passes from If we put some pressure on the salty water restrictions? Are you located in a dilute (or fresh) to a more side, it will slow down or prevent an area where there is not sufficient concentrated solution across a semi- osmosis from occurring. Ifwe put more to supply your irrigation permeable . The membrane pressure on the salty side, we will not needs? is a barrier that allows the passage of only prevent osmosis, but we will cause Even if you are surrounded on all water , but not the passage of water to flow in the other direction, and sides by brackish or water, there is dissolved solids in the water. this is called reverse osmosis. an option available that can provide Let's say there are two containers, The reverse osmosis water treatment plenty of fresh irrigation water and one with fresh water and the second process applies enough pressure to a save money. For golf courses in coastal with salty water filled to the same level salty water supply to make pure water areas or other areas with only brackish and connected to the first container flow through a membrane. The saltier water available, this water can be by a semi-permeable membrane. The the supply water, the higher the pres- effectively purified using the reverse natural tendency is for the two solu- sure needed to produce the water. All

NOVEMBERIDECEMBER 1998 5 reverse osmosis process systems have humming away on the RO wanted to save money on water, which some degree of pre-treatment needed to system. Operators do not need to be was getting expensive, but we also condition the water to minimize plug- present during plant operation, and wanted to control our water supply and ging or of the . Most they only need to make periodic checks protect our investment." membrane elements today can remove to monitor the system. In fact, to save Miller Engineering evaluated the up to 99.5 percent of the salt from the on power, which is the single largest situation and recommended the most water. operating cost, the system was designed cost-effective solution. In this case, In this article, we will look at two to operate at night to take advantage there was no shallow brackish ground- golf courses that have built treatment of lower, off-peak power rates from the water, but there was brackish ground- systems and now make their irrigation electric utility. water 1,500 feet down. A deep was water. We also will discuss how you can Peter Brooks has been operating the constructed to supply the' brackish evaluate whether this option is right system for more than two years. Using to a new 200,000-gallon- for your course. 100 percent treated water on the golf per-day RO treatment plant (expand- course, operating costs to produce able to 400,000 gpd). The well was The Everglades Club: Making water are now averaging about 40drinking water for irrigation, was faced with similar, but more severe was not a problem." Operating costs to and for environmental reasons wanted water problems. While they have a produce water are comparable to the to help preserve the limited fresh large freshwater reservoir for storage Everglades Club, and the savings are groundwater. Peter Brooks, golf course of irrigation water, the only source for substantial. Moreover, the club now superintendent for the Everglades the fresh water is limited stormwater has control over the supply and quality Club, was placed in charge of finding runoff and a water pipe from the local of its irrigation water. a solution. Brooks said, "Our water water utility located on the other side bills were going through the roof. We of the Intracoastal Waterway. Not only were water rates going up, but availa- Is Reverse Osmosis knew we had to do something. When Right for Your Course? water restrictions came out, we knew bility of water also was an issue. Rob the time to act was now." I

6 USGA GREEN SECTION RECORD expenses include electricity, treatment chemicals, prefilter cartridges, and periodic cleaning chemicals. Normally, additional staff is not added strictly for the plant, so labor is not an oper- ating expense. Operating expenses for brackish water systems will run 30<1:to 50<1:per 1,000 gallons produced. Elec- tricity for a brackish plant will be about 50 percent of the total operating cost. Another recurring expense is replacement of the membrane elements in the treatment system. Elements cost about $500 to $700 each and are guaranteed for three years, but most installations can and do achieve ele- ment lives of more than 10 years. Set- ting aside funds for 6-year membrane replacement life will add about 8<1:per 1,000 gallons. "l A payback analysis is normally per- Peter Brooks, CGCS, is at the computer controls of the reverse osmosis plant at the formed to estimate how long it will take Everglades Club on the Island of Palm Beach (Florida). While the system is fully to repay the capital costs from the automated, Mr. Brooks has found that additional savings in production costs can be savings achieved in operating expenses achieved with fine-tuning of the system. versus water bills. Most brackish water irrigation plants in Florida will pay to consider in evaluating whether it dispose of the unused, concentrated themselves back in seven to nine years. will make sense to make your own water from the system (industrial Making irrigation water with an RO water. discharge permit). The water use per- system has some substantial financial mit is a straightforward process that benefits for most golf courses that cur- Water Supply normally takes three to five months to rently purchase irrigation water. These The most important thing to look at obtain. benefits can be more accurately esti- is your available water. If you have The industrial discharge permit may mated by performing a financial feasi- adequate fresh water from wells or take from three to nine months to bility analysis during the preliminary other sources, treatment is not needed, obtain, depending on the individual phase of the project. and future use of this supply is not site circumstances. It is therefore im- threatened, you probably don't need to portant that during the initial feasibility In Closing consider RO for your course. However, period, the most cost-effective brine We have presented examples of golf if you have water that is unusable be- disposal method is selected. The brine courses that are achieving substantial cause of high hardness or alkalinity, a waste from the RO plant is crystal clear benefits by making their own irrigation special type of RO system termed mem- and poses no health threat, but en- water. These and other benefits can brane softening may be appropriate. vironmental regulatory agencies want help solve your water problems. How- Reverse osmosis treatment can be the disposal process permitted. ever, it is important that any golf course performed on water with any , hire professionals experienced in com- from brackish to straight . Financial Evaluation pleting these unique projects from start Operating costs will increase as the Evaluation of the financial aspects of to finish. The entire process will take water salinity increases, due to the the RO treatment system involves an from 12 to 24 months from concept to higher pressures that need to be analysis of the capital costs and the producing water, and a committed pumped to achieve the treatment. In operating costs. Capital costs involve team of professionals is important. addition, seawater systems generally the cost incurred to construct the produce only 1.5 to 2.0 gallons of fresh system. These include soft costs The author wishes to acknowledge Peter water for every 4 gallons of feed water. (mainly engineering fees and permit Brooks, golf course superintendent at The water generally will cost 4 to 7 fees) and hard costs. For an RO plant, Everglades Club, Jim St. John, managing times more to treat than lower-salt, the major hard costs are the supply director at the Jupiter Island Club, and Rob Kloska, golf course superintendent at brackish water. Therefore, you want to wells, treatment building, brine dis- Jupiter Island Club, for their contributions select a water supply that is plentiful posal system, treatment equipment, to this article. and has the lowest salinity. , and piping. For a typical RO plant to supply irrigation water for a Permitting golf course, capital costs will run about GLEN A. MILLER, PE, is a senior pro- RO treatment plants in Florida that $1.50 to $3.00 per gallon. For a fessional engineer and President of Miller Engineering, a company specializing in are used to produce irrigation water do 500,000-gallon-per-day brackish water the planning, permitting, design, and con- not require a special permit to con- system, total capital costs will be in the struction of reverse osmosis water treat- . struct. However, special permits are $1.0 million to $1.4 million range. ment plants. Mr. Miller has been involved required to withdraw groundwater Operating costs include the ongoing with the design of water treatment projects (water use permit) and to properly expenses to produce the water. These for more than 20 years.

NOVEMBER/DECEMBER 1998 7