The filtration vessels are at the heart of the reverse osmosis water treatment process. For everyfour gallons of brackish water treated, three gallons of usable water is produced.

USING REVERSE OSMOSISTO MAIm IRRIGATION WATERThe reverse osmosis water treatment process can turnbrackish water into a valuable resource for golf courses.by GLEN A. MILLER

WATER is perhaps the mostprecious resource for anygolf course, and a reliable,

economical supply of good quality irri-gation water should be a priority forevery course. What is the water situ-ation at your course? Are you buyingyour irrigation water, and is the cost ofwater becoming a real budget issue?Do you have to curtail watering due towater restrictions? Are you located inan area where there is not sufficientfresh water to supply your irrigationneeds?

Even if you are surrounded on allsides by brackish or salt water, there isan option available that can provideplenty of fresh irrigation water andsave money. For golf courses in coastalareas or other areas with only brackishwater available, this water can beeffectively purified using the reverse

osmosis (or "RO") water treatmentprocess.

What is Reverse Osmosis?To understand reverse osmosis, one

must first understand osmosis. Osmosisis a naturally occurring phenomenonthat is all around us. The cells in yourbody get water via osmosis. Osmosis isthe process by which water passes froma dilute (or fresh) solution to a moreconcentrated solution across a semi-permeable membrane. The membraneis a barrier that allows the passage ofwater molecules, but not the passage ofdissolved solids in the water.

Let's say there are two containers,one with fresh water and the secondwith salty water filled to the same leveland connected to the first containerby a semi-permeable membrane. Thenatural tendency is for the two solu-

tions to achieve the same concentra-tion. To do this, water from the freshside would pass to the salty side andthis would continue until they reachedan equilibrium. At the end, the waterlevel on the original salty side will behigher (and now less salty), and thiswater height difference is called theosmotic pressure.

If we put some pressure on the saltyside, it will slow down or preventosmosis from occurring. Ifwe put morepressure on the salty side, we will notonly prevent osmosis, but we will causewater to flow in the other direction, andthis is called reverse osmosis.

The reverse osmosis water treatmentprocess applies enough pressure to asalty water supply to make pure waterflow through a membrane. The saltierthe supply water, the higher the pres-sure needed to produce the water. All

NOVEMBERIDECEMBER 1998 5

reverse osmosis process systems havesome degree of pre-treatment needed tocondition the water to minimize plug-ging or fouling of the membranes. Mostmembrane elements today can removeup to 99.5 percent of the salt from thewater.

In this article, we will look at twogolf courses that have built treatmentsystems and now make their irrigationwater. We also will discuss how you canevaluate whether this option is rightfor your course.

The Everglades Club: MakingWater and Saving 75 Percent

Located on the Barrier Island ofPalm Beach on the lower southeastcoast of Florida, a beautiful golf coursehas been maintained at the EvergladesClub since the early 1920s. Surroundedby the Atlantic Ocean and the Intra-coastal Waterway, the course has nofresh water and has to purchase potablewater to irrigate the course. With thecost of water rising and no end insight, the club wanted to do somethingto lower its water bills. In addition,the club recognized that it was usingpristine drinking water for irrigation,and for environmental reasons wantedto help preserve the limited freshgroundwater. Peter Brooks, golf coursesuperintendent for the EvergladesClub, was placed in charge of findinga solution. Brooks said, "Our waterbills were going through the roof. Weknew we had to do something. Whenwater restrictions came out, we knewthe time to act was now."

Miller Engineering was brought in toevaluate the situation and recommenda solution. The solution was for theclub to start making its own water.Although there was no fresh wateraround, there was plenty of salt orbrackish water. Miller Engineeringdesigned a water plant that would usethe reverse osmosis treatment processto remove the salt from the brackishgroundwater and produce water fresherthan they were currently buying.

The treatment plant was designed toproduce 600,000 gallons of fresh waterper day. On-site shallow wells wereinstalled to supply brackish ground-water to the plant. For every fourgallons of brackish well water, theplant produces three gallons of freshwater. The treatment system is com-puter controlled and is designed tooperate automatically. All of the equip-ment is housed in a building con-structed on the eastern edge of theproperty. The only noise is the feed

6 USGA GREEN SECTION RECORD

pump humming away on the ROsystem. Operators do not need to bepresent during plant operation, andthey only need to make periodic checksto monitor the system. In fact, to saveon power, which is the single largestoperating cost, the system was designedto operate at night to take advantageof lower, off-peak power rates from theelectric utility.

Peter Brooks has been operating thesystem for more than two years. Using100 percent treated water on the golfcourse, operating costs to producewater are now averaging about 40<!:to45<!:per 1,000 gallons. This cost com-pares to $3.18 per 1,000 gallons forpotable water. With the RO systemproducing fresh irrigation water, theclub is saving more than 75 percent ofthe cost previously paid to purchasewater from the town. The expectedpayback for the irrigation water treat-ment system is about five years.Jupiter Island Club:Going Deep for Savings

Located about 20 miles north ofPalm Beach, the Jupiter Island Clubwas faced with similar, but more severewater problems. While they have alarge freshwater reservoir for storageof irrigation water, the only source forthe fresh water is limited stormwaterrunoff and a water pipe from the localwater utility located on the other sideof the Intracoastal Waterway. Not onlywere water rates going up, but availa-bility of water also was an issue. RobI<loska, golf course superintendent,recalls, "We were starting to see dayswhen the utility company shut us downduring drought conditions when weneeded water the most. With more than100 acres of golf course and landscapeto irrigate, water is critical. We have alot invested in plant material. We

A 1,500-foot-deep artesianwell supplies

brackishwater to the

reverseosmosis plantat the Jupiter

Island Club(Jupiter,

Florida).

wanted to save money on water, whichwas getting expensive, but we alsowanted to control our water supply andprotect our investment."

Miller Engineering evaluated thesituation and recommended the mostcost-effective solution. In this case,there was no shallow brackish ground-water, but there was brackish ground-water 1,500 feet down. A deep well wasconstructed to supply the' brackishgroundwater to a new 200,000-gallon-per-day RO treatment plant (expand-able to 400,000 gpd). The well wasunder pressure ("artesian"), whichmeant that a pump did not have to beplaced down the well. To save payrollcosts, the plant was designed to operate24 hours per day and limited computer-ized operations were incorporated.

The plant has been in operationsince April 1998. The treatment build-ing was designed to be unobtrusive andis located directly on the golf course.Jim St. John, managing director, notes,"Putting the building in the middle ofthe course, next to the irrigation lake,made a lot of sense. We had to makesure we could hide it from view, whichwas not a problem." Operating costs toproduce water are comparable to theEverglades Club, and the savings aresubstantial. Moreover, the club nowhas control over the supply and qualityof its irrigation water.

Is Reverse OsmosisRight for Your Course?

As cited above, you do not have tobe a water treatment utility with experi-enced operators to consider usingreverse osmosis treatment to produceirrigation water. Most systems operateautomatically so that constant atten-tion and maintenance are not required.However, several issues are important

GLEN A. MILLER, PE, is a senior pro-fessional engineer and President of MillerEngineering, a company specializing inthe planning, permitting, design, and con-struction of reverse osmosis water treat- .ment plants. Mr. Miller has been involvedwith the design of water treatment projectsfor more than 20 years.

expenses include electricity, treatmentchemicals, prefilter cartridges, andperiodic cleaning chemicals. Normally,additional staff is not added strictlyfor the plant, so labor is not an oper-ating expense. Operating expenses forbrackish water systems will run 30<1:to50<1:per 1,000 gallons produced. Elec-tricity for a brackish plant will beabout 50 percent of the total operatingcost. Another recurring expense isreplacement of the membrane elementsin the treatment system. Elements costabout $500 to $700 each and areguaranteed for three years, but mostinstallations can and do achieve ele-ment lives of more than 10 years. Set-ting aside funds for 6-year membranereplacement life will add about 8<1:per1,000 gallons.

A payback analysis is normally per-formed to estimate how long it will taketo repay the capital costs from thesavings achieved in operating expensesversus water bills. Most brackish waterirrigation plants in Florida will paythemselves back in seven to nine years.

Making irrigation water with an ROsystem has some substantial financialbenefits for most golf courses that cur-rently purchase irrigation water. Thesebenefits can be more accurately esti-mated by performing a financial feasi-bility analysis during the preliminaryphase of the project.

In ClosingWe have presented examples of golf

courses that are achieving substantialbenefits by making their own irrigationwater. These and other benefits canhelp solve your water problems. How-ever, it is important that any golf coursehire professionals experienced in com-pleting these unique projects from startto finish. The entire process will takefrom 12 to 24 months from concept toproducing water, and a committedteam of professionals is important.

The author wishes to acknowledge PeterBrooks, golf course superintendent at TheEverglades Club, Jim St. John, managingdirector at the Jupiter Island Club, andRob Kloska, golf course superintendent atJupiter Island Club, for their contributionsto this article.

dispose of the unused, concentratedbrine water from the system (industrialdischarge permit). The water use per-mit is a straightforward process thatnormally takes three to five months toobtain.

The industrial discharge permit maytake from three to nine months toobtain, depending on the individualsite circumstances. It is therefore im-portant that during the initial feasibilityperiod, the most cost-effective brinedisposal method is selected. The brinewaste from the RO plant is crystal clearand poses no health threat, but en-vironmental regulatory agencies wantthe disposal process permitted.

Financial EvaluationEvaluation of the financial aspects of

the RO treatment system involves ananalysis of the capital costs and theoperating costs. Capital costs involvethe cost incurred to construct thesystem. These include soft costs(mainly engineering fees and permitfees) and hard costs. For an RO plant,the major hard costs are the supplywells, treatment building, brine dis-posal system, treatment equipment,pumps, and piping. For a typical ROplant to supply irrigation water for agolf course, capital costs will run about$1.50 to $3.00 per gallon. For a500,000-gallon-per-day brackish watersystem, total capital costs will be in the$1.0 million to $1.4 million range.

Operating costs include the ongoingexpenses to produce the water. These

to consider in evaluating whether itwill make sense to make your ownwater.

"l

Peter Brooks, CGCS, is at the computer controls of the reverse osmosis plant at theEverglades Club on the Island of Palm Beach (Florida). While the system is fullyautomated, Mr. Brooks has found that additional savings in production costs can beachieved with fine-tuning of the system.

Water SupplyThe most important thing to look at

is your available water. If you haveadequate fresh water from wells orother sources, treatment is not needed,and future use of this supply is notthreatened, you probably don't need toconsider RO for your course. However,if you have water that is unusable be-cause of high hardness or alkalinity, aspecial type of RO system termed mem-brane softening may be appropriate.

Reverse osmosis treatment can beperformed on water with any salinity,from brackish to straight seawater.Operating costs will increase as thewater salinity increases, due to thehigher pressures that need to bepumped to achieve the treatment. Inaddition, seawater systems generallyproduce only 1.5 to 2.0 gallons of freshwater for every 4 gallons of feed water.Sea water generally will cost 4 to 7times more to treat than lower-salt,brackish water. Therefore, you want toselect a water supply that is plentifuland has the lowest salinity.

PermittingRO treatment plants in Florida that

are used to produce irrigation water donot require a special permit to con-struct. However, special permits arerequired to withdraw groundwater(water use permit) and to properly

NOVEMBER/DECEMBER 1998 7