A Step-By-Step Guide For Using Recycled Water An outline of the costs and maintenance practices necessary to manage this valuable resource.

BY PATRICK J. GROSS

Water is fast becoming the new gasoline. Turf has to have it, and at the same time the supply continues

to decline and the costs keep going up. As the water crunch becomes more severe in various regions of the United States, there is heightened awareness that conservation and the use of recycled water are necessary and viable alterna­tives for the irrigation of golf courses and large turf areas.

Changing from potable water to recycled water is not an even proposition. Despite the advances in treatment technology, high levels of soluble salts and sodium contained in the water continue to be a major concern when used to irrigate sensitive turfgrass species and landscape plants. Extra maintenance practices must be employed to counteract the negative impacts of salts and sodium, and these practices add time, labor, and expense to the maintenance operation.

Books and articles have been published about how to manage turf irrigated with recycled water, many of which focus on the complex chemical interactions in the soil and water matrix. Once the chemical formulas and mathematical equations start flying, many practitioners throw up their hands. Managers and owners simply want to know the specific practices needed to manage recycled water and how much it will cost. Although the quality of recycled water and necessary management practices vary greatly from region to region, some basic guidelines should be used when irrigating with recycled water. This article offers a step-by-step approach for using recycled water and an estimate of the associated costs based on the experiences of 13 golf courses in the southwestern United States.

SOIL AND WATER TESTING Routine soil and water testing is a cornerstone of successfully managing the use of recycled water.

Where recycled

water is used,

vegetative buffer

areas around lakes

help reduce

infestations of algae

and aquatic weeds

along shorelines.

As the water crunch

becomes more severe,

there is heightened

awareness that

conservation and the

use of recycled water

are necessary and viable

alternatives for golf

course irrigation.

M A R C H - A P R I L 2 0 0 8 I

(Top) Problems withalgae and aquatic weedgrowth can be reducedor eliminated by storingrecycled water in acovered reservoir.

Although laboratory reports may be confusing tosome, the information provided by these reportsprovides a history of soil and water quality and isa valuable tool for implementing preventivemaintenance practices and preserving turfquality. The main concerns with recycled waterare the increased levels of soluble salts, sodium,bicarbonates, and heavy metals that can have anegative impact on soil structure and directlyaffect sensitive turf grass species and landscapeplants. The method and frequency of testing isvery important. Most recycled water producerswill freely share monthly water quality reports

(Above) Aquatic weedgrowth can be prolificin storage reservoirsdue to the increasednutrient content ofrecycled water.

2 GREEN SECTION RECORD

with their customers; however, these reports arefocused on health quality standards and typicallydo not provide enough information regardingagricultural suitability. Successful users ofrecycled water work with an independent soiland water testing laboratory that is familiar withsaline and sodic soil conditions as well as golfcourse requirements. It is important to be awarethat various laboratories may use different pro-cedures for analyzing soil and water samples. It isgenerally recommended that the laboratory fol-low procedures developed by the United StatesSalinity Laboratory, including the use of a satu-rated paste extract for determining Ee (electro-conductivity) and SAR (sodium adsorptionratio), which is the standard reference used fordetermining thresholds and managementrecommendations in the scientific literature(Carrow, Duncan, 1998).

Superintendents who manage recycledwater have implemented a variety of strategiesfor monitoring soil and water quality. Watersampling should be performed at least four timesper year, and soil sampling a minimum of twotimes per year, including representative samplesfrom tees, greens, and fairways. A more accurateapproach recommended by Stowell and Gelernteris to arrange for an annual aerial photograph tobe taken of the golf course to identify weak areasand evaluate the impact on trees. Once the aerialphotograph has been analyzed, at least ten soilsamples from fairways should be taken in bothgood and bad areas to provide a comparison ofsoil chemical properties (PACE, 1999). Overtime, the information provided by these reports

can help to identify trends and aid in the develop-ment of preventive maintenance programs.

Another useful monitoring technique is topurchase a portable Ee meter and moisturesensing equipment that can be used in the fieldto provide instant feedback on soil salinity andmoisture content. Although these instrumentsare not as accurate as laboratory testing equip-ment, they provide an acceptable amount ofinformation on which to base managementdecisions (Vermeulen, 1997).

The superintendents surveyed offered thefollowing information regarding the frequencyand annual cost for soil and water testing alongwith the purchase of monitoring equipment:• Total cost for monthly water sampling and soiltesting two to four times per year - $2,000.• Portable Ee meter - $350.41) Soil moisture probe - $900.

During the early phases of planning for theconversion to recycled water, some courses havesuccessfully negotiated agreements to have therecycled water provider pre-treat the water priorto delivery or arrange the periodic delivery offresh water for leaching fairways. In some partsof the southwestern United States, water agenciesappear to be more willing to treat the water priorto delivery to help meet health and safety stand-ards as well as improve agricultural suitabilityfor their customers. The following is a generalestimate of the cost for various on-site watertreatment programs:• Gypsum injection - Equipment costs $7,000to $15,000; gypsum costs $10,000 to $20,000per year.e Sulfuric generator - Equipment costs $12,000to $16,000; sulfur costs $3,000 to $5,000 ormore per year.

• Three to four hours of labor per week formonitoring from May through November.• Aerial photograph - $1,200 per year.

WATER TREATMENTNot all recycled water requires treatment. Theneed for treatment and the specific methoddepend on an analysis of the soil and water by anindependent laboratory familiar with saline andsodic conditions. A variety of treatment optionshave been used successfully to improve recycledwater, including gypsum injection, sulfuric acidinjection, the use of a sulfurous generator, andblending. The cost of treatment, if necessary,varies widely based on the soil and water condi-tions at each site.

• Sulfuric acid injection - Equipment costs$15,000 to $18,000; acid costs $8,000 to$25,000 per year.• Water blending - Equipment cost is variable;operation costs $10,000 to $50,000 or more peryear.• Wetting agents - $8,000 to $10,000 per year(Gross, 2003).

Proper design, alongwith the use offountains, bubblers,and other circulationdevices, can minimizealgae and aquaticweed growth in lakeswhere recycledwater is stored.

LEACHING TO CONTROLSOLUBLE SALTSDue to the higher levels of total dissolved salts,sodium, and other constituents, the applicationof extra water over and above normal irrigationrequirements (leaching) typically is required topreserve healthy turf growth. The overall goal is

MARCH-APRIL 2008 3

to maintain a net downward movement of waterand salts to prevent harmful concentrations inthe rootzone (Harivandi, 2007). Although manywater agencies sell recycled water for 15% to20% less than potable water, many superinten-dents report having to use 10% to 20% morewater for leaching programs to control solublesalts - a break-even proposition.

Prerequisites for an effective leachingprogram include an irrigation system withgood distribution uniformity and a regularon-site monitoring program so that leach-ing can be performed before any visibleturf grass damage occurs (Huck, 2000).

Leaching strategies vary based on siteconditions, the demands of the golfingschedule, and the preference/experienceof the superintendent. The overall goal is tokeep the accumulation of soluble salts belowthe damage threshold for the specific turfspecies/variety being grown. This can bedone in several ways:• Periodic leaching with good qualitywater .• Including a leaching fraction (extra water)as part of normal irrigation applications... Periodic deep watering with the existingrecycled water source, using multiple cyclesof 15 to 30 minutes with 1 to 2 hoursbetween cycles (Carrow and Duncan,1998)./I The use of low- precipitation-ratesprinklers for 8 to 12 hours.

Soil salinity must be monitored in thefield before and after leaching to determineif salts have been moved effectively beyondthe rootzone. The use of a handheld port-able EC meter is invaluable in this regard.Some practitioners incorrectly assume thatsimply doubling the amount of time onthe irrigation controllers for a single nightwill provide effective leaching. Throughfrequent sampling and monitoring, many

superintendents have found that this is not nearlyenough water to control soluble salt accumula-tion and that leaching may need to be performedover two to three consecutive nights.

The costs associated with a successful leachingprogram will depend on water quality, prevail-ing site conditions, and the cost of water. Thefollowing is a general estimate of the extra waternecessary for leaching programs. The added costwill depend on the price of water at each site:

4 GREEN SECTION RECORD

• Greens - In the Southwest, heavy leaching istypically performed monthly from May throughNovember. The amount of water and the associ-ated costs varied among the courses surveyed,but generally it was in the range of 10% to20% additional water over and above normalirrigation requirements... Fairways and tees - Typically, 10% to20% additional water over and above normalirrigation requirements.

AERATION, ORAlAND TOPDRESSINGPrograms for aeration, drainage improvement,and sand topdressing are of particular importancein the successful management of recycled water.The overall goal is to improve soil propertiesto enhance water penetration and percolation,allowing for the removal of soluble salts fromthe rootzone. Aeration frequency needs to beincreased, especially in spring and early summer,so that the turf is healthy and able to withstandheat stress and the increasing salt accumulationthat typically occurs in late summer and earlyfall (Huck, 2000). Deep aeration on fairwayshas become a standard program at sites usingrecycled water. Although more disruptive andtime consuming, this form of aeration does abetter job of relieving soil compaction and pro-viding deep channels for the incorporation ofgypsum or other soil amendments to preservesoil structure. Various forms of cultivation aretypically employed at more frequent intervalson greens, tees, and fairways. Coring and deep-tine aeration in the spring and fall remain thecornerstone of most successful programs. This istypically supplemented at monthly intervals withspiking, slicing, quadratine, or venting tech-niques to keep surfaces open for gas exchangeand to accept larger volumes of water.

Drainage is another essential program fordealing with salt and sodium accumulation.Damage is most prominent in low-lying sectionsof the course where water accumulates, resultingin a higher concentration of soluble salts andsodium once the water evaporates. The installa-tion of drainage inlets and subsurface drainpipecan help to remove this excess water and preventthe toxic buildup of salts and sodium.

Sand topdressing of fairways is another pro-gram that has become popular throughout theSouthwest in an effort to improve playingquality, traffic tolerance, turf health, and allow

for the rapid removal of excess water. Manycourses have implemented a fairway topdressingprogram, regardless of whether they are usingrecycled water, in an effort to improve year-round playing quality. A topdressing program isnot essential in the management of recycledwater; however, it does make it easier to leachsalts and sodium while providing firmer turfconditions immediately after deep wateringcycles.

The survey indicated the following extrapractices and costs associated with aeration,drainage, and topdressing where recycled wateris used:CIt Greens - An average of three extra aerationtreatments per year.e Fairways - An average of two extra aerationtreatments per year.e Deep aeration of fairways - One to twotimes per year at an average cost of $10,000 to$11,000 per treatment .• Drainage improvement - $5,000 to $10,000per year .• Fairway topdressing - $25,000 to $65,000per year.

FERTILITY AND SOIL AMENDMENTSParticular attention must be paid to fertilityand the application of soil amendments whenusing recycled water. The type and quantity offertilizer and amendments should be based onroutine soil and water quality tests. Whensignificant amounts of sodium are present in thesoil, it is typically recommended to apply acalcium-based soil amendment, such as gypsum,at routine intervals. The incorporation of gypsumin conjunction with aeration and leaching helpsto preserve soil structure. Many courses surface-apply gypsum to greens in conjunction withmonthly spiking or venting, followed by a heavyleaching cycle.

Another strategy typically employed by super-intendents who use recycled water is the routineapplication of a soil wetting agent. Such productshelp to maintain good water infiltration andpercolation, helping flush salts and sodium awayfrom the turfgrass rootzone.

Recycled water may contain a significantamount of nutrients, including nitrogen, phos-phorus, and potassium. It is important to trackthe seasonal variations of nutrients that may becontained in the water and adjust fertility pro-grams accordingly (Huck, 2000). Frequent

leaching also can deplete mobile elements, suchas potassium, and it is often necessary to makesupplemental potassium applications followingleaching cycles.

Superintendents surveyed reported the follow-ing costs and/or savings with regard to fertilityand the application of soil amendments:• Fertilizer savings - Only two of the coursesreported an annual savings of$7,000 to $9,000per year due to the nutrient content of recycledwater. The other courses noted negligibleimpacts.e Additional costs for fertilizer - One of thecourses surveyed reported an increased cost of$3,000 to $5,000 per year for the application ofpotassium and micronutrients.• Gypsum applications - $5,000 to $30,000per year (the higher cost is typically associatedwith multiple applications to fairways by acontract applicator).

By necessity, sitesusing recycled watermust apply extrawater to control soilsalts and sodiumlevels. Soil conditionsneed carefulmonitoring by usingportable testingdevices such as themoisture probe(opposite page),used to monitor soilmoisture levels, andan EC meter (above),used in monitoringsoluble salt levelsto help maintainthe critical balancebetween healthy turfgrowth and goodplaying quality.

IMPACTS ON TURF QUALITYAND PLAYING CONDITIONSThe use of recycled water affects turf quality andplaying conditions in several ways:

MARCH-APRIL 2008 5

When significant amounts of sodium are present in the soil, typically it is necessary toapply a calcium-based soil amendment, such as gypsum, at routine intervals. Customapplication on a frequency of two times per year can cost approximately $30,000.

Fairway sand topdressing can improve soil properties, making it easier to leach salts andsodium while providing firmer turf conditions immediately after deep watering cycles. Thecost of an effective topdressing program is approximately $25,000 to $60,000 per year.

Deep aeration on greens, using 5;;6" needle tines, has become a popular program toenhance water p,ercolation and allow for the removal of soluble salts from the rootzone.

6 GREEN SECTION RECORD

.. Some turf species are more susceptible tosalinity damage.• Generally wetter turf conditions as a result ofleaching programs.• Additional costs are associated with supple-mental seeding or sodding to repair areasdamaged by salinity stress.• Courses that conduct winter overseedingreport using higher seeding rates to compensatefor seedling mortality as a result of the highersalt content of the water.

Another issue faced by many older golfcourses is the management of native soil greensthat lack a subsurface drainage system. Suchgreens are more susceptible to damage due tosalt and sodium accumulation and the difficultyof leaching these components from the soilprofile (Moore, 1994). In such circumstances,many courses have chosen to install a separatepiping system to provide potable waterexclusively for the greens. If this is not feasible,frequent deep-tine aeration or possible puttinggreen reconstruction could be the only remedy.

Of the courses surveyed, few have attemptedto convert fairways to a more salt-tolerantspecies, preferring to manage their existingmixture of grasses. Although converting to amore salt-tolerant turf variety such as bermuda-grass or seashore paspalum is an effective strategy,the cost and disruption of such a project isviewed as prohibitive by many courses. A few ofthe courses surveyed have incorporated conver-sion to a more salt-tolerant turf variety as part offuture golf course remodeling plans.

Survey responses regarding the cost associatedwith turf repair and renovation are as follows:• Sod for damaged areas - $10,000 per year.• Increased costs for winter overseeding -$3,000 to $20,000 per year.• Conversion to a more salt-tolerant turf grassvariety (including the cost of sod, soil improve-ment, and drainage) - $20,000 to $30,000 peracre.

IRRIGATION SYSTEMRETROFITTING, MAINTENANCE.AND REPAIRDue to the sensitive nature of Poa annua andcreeping bentgrass putting greens, many courseshave reconfigured the irrigation system toinclude a separate supply line to deliver potablewater to the greens. Since greens typically com-prise 2% to 4% of the total golf course acreage, it

is a relatively cost-efficient solution to preservingturf quality on this important area of the course.

A slightly higher cost can be expected formanaging the irrigation system where recycledwater is used. The costs can differ based on theage and design of the irrigation system andwhether the water is delivered under pressure orneeds to be pumped. Due to the higher saltcontent, recycled water can be corrosive to metalcomponents typically used in irrigation pumpsand valves. There also are additional costs associ-ated with regulatory compliance for annual crossconnection checks to ensure that the pipingsystems for potable and recycled water are notinterconnected.

Survey responses regarding maintenance andrepair of the irrigation system varied based onthe age and design of the system, with manycourses reporting no additional costs for mainte-

nance and repair. Regulatory compliance andcosts for other items are as follows:• Regulatory compliance and cross connectioncheck - $150 to $400 per year.• Accelerated wear on pumps and valves(approximately 50%) - $6,000 per year.• Repair of plugged irrigation heads - $5,000per year.• Installation of a separate piping system to -provide fresh water to the greens - $250,000 to$300,000.

MANAGING LAKESLakes and reservoirs for the storage of recycledwater present a major challenge for superinten-dents. The increased nutrient content of thewater provides a perfect environment for therapid growth of algae and aquatic weeds, whichdetract from the general appearance of the water

The lack of waterpenetration may bea sign that watertreatment is necessary.A variety of treatmentoptions are available,from gypsum injectionto sulfuric acid injection,at a cost of $3,000 to$25,000 per year,depending on the typeof treatment required.

MARCH-APRIL 2008 7

(Above left) Salt andsodium accumulationcan cause the declineof sensitive turfspecies, especiallyin low areas. Somecourses spendapproximately$10,000 per year forsod to repair thesedamaged areas.

(Above right)Routine chemicalwater testing isessential whererecycled water isused. The total costfor monthly watersampling and soiltesting two to fourtimes per year isapproximately$2,000.

features. Proper design of the lakes and reservoirscan help reduce many of these problems. Depthsshould be at least 10 to 12 feet or more to reducesunlight penetration and maintain cooler watertemperatures throughout the year (Gill andRainville, 1994). If given the opportunity todesign the lakes prior to the delivery of recycledwater, it is recommended to provide at least fivedays of water storage capacity and provideshading along the banks with trees, shrubs, andvegetative buffer strips (Terry, 1994).

Problems associated with algae and aquaticweeds can be reduced or eliminated by havingthe water delivered under pressure directly intothe mainline piping system. As an alternative,some courses store recycled water in tanks orcovered reservoirs.

Survey responses with regard to managinglakes revealed the following information:• Treatment for algae and aquatic weeds -$20,000 to $40,000 per year.

CONCLUSIONThe key word to keep in mind with regard tothe management of recycled water is adjustment.There need to be adjustments in budgets,management practices, and golfer expectationsif recycled water is to be used effectively. Rarelydoes one find the ideal scenario of sandy soilconditions, perfect drainage, and salt-tolerantturf species. Usually it is a mixed bag of condi-tions that the superintendent must manage toachieve the best possible playing conditionsgiven the circumstances. The biggest issueremains the management of soluble salts andsodium that are inherent in most recycledwaters. Special attention must be given toregular soil and water quality monitoring,

8 GREEN SECTION RECORD

aeration, leaching, and developing a soundstrategy for the application of soil amendments.

Is it possible to have championship golfingconditions with the use of recycled water? Theanswer is definitely yes! Three future U.S. Openvenues currently use recycled water, includingTorrey Pines (2008), Pebble Beach (2010), andThe Olympic Club (2012). As these courseshave done, a step-by-step approach to managingrecycled water can address agronomic concernswhile still providing good playing quality.

REFERENCESCarrow, R. N., R. R. Duncan. 1998. Salt Affected TuifgrassSites: Assessment and Management. Ann Arbor Press.Chelsea, Mich.Gross, Patrick]. 2003. USGA Green Section Record.May/June. 41(3):17-20.Harivandi, Ali. 2007. Golf Course Management. June.75(6):98-108.Huck, Michael, R. N. Carrrow, R. R. Duncan. 2000.USGA Green Section Record. March/April. 38(2):15-29.Huck, Michael. 1994. In: Wastewater Reusefor Golf CourseIrrigation. Lewis Publishers, Ann Arbor, Mich. pp.242-247.Gill, Garrett, D. Rainville. 1994. In: Wastewater ReuseforGolf Course Irrigation. Lewis Publishers, Ann Arbor, Mich.pp.44-52.Stowell, Larry]., W. Gelernter. 1999. PACE Insights.5(3):1-4.Terrey, Andrew. 1994. In: Wastewater Reuse for Golf CourseIrrigation. Lewis Publishers, Ann Arbor, Mich.pp. 130-142.Vermeulen, P. 1997. USGA Green Section Record.September/October. 35(5):16.

PAT GROSS joined the USGA Green Section in 1991and is the director if the Southwest Region) wherewater availability and the use if recycledwater aremajor issues.