Keeping It Green
RO treatment system keeps golf course grass healthy
Perhaps the most attractive aspect of golfing is the idea of spending several hours in a park-like setting strolling across lush fairways, putting greens and tees. For this reason, golf course managers dedicate a great deal of resources to the maintenance and health of special turf grasses.
Irrigation water with approximately 400 parts per million (ppm) total dissolved solids (TDS) contains the right mix of minerals for healthy turf. If irrigation feed source contains too much sodium, for example, it can detrimentally affect the turf physically and chemically. Soils with an accumulation of exchangeable sodium often are characterized by poor tithe and low permeability, making them unfavorable for plant growth. Golf course superintendents are familiar with the sodium absorption ratio (SAR) and they desire a low SAR index.
At Spirit Hollow Golf Course, high TDS and high SAR made turf maintenance a nightmare.
Spirit Hollow is a public daily fee course in Burlington, Iowa, about an hour south of the Quad Cities, and almost equidistant from Chicago; Des Moines, Iowa; and St. Louis. The upscale 18-hole track plays mostly through a small river valley that contributes to its picturesque holes and significant elevation changes. The course conditioning is top notch, with bent grass tees, fairways and greens.
During periods of abundant rain, there is plenty of acceptable water available in the lake, which is then pumped onto the property for irrigation. Unfortunately, the six-month golf season coincides with seasonal drought conditions. With little water remaining in the lake, the golf course superintendent supplements lake water with water from a well that flows approximately 700 gal per minute and contains approximately 2,800 ppm TDS. This brackish water is unacceptable for golf course irrigation and was detrimental to the turf grass, fairways and tees, making the property unattractive in appearance and playability.
Spirit Hollow contacted consulting firm Water Treatment Systems Inc. (WTS) of Boca Raton, Fla., in search of a solution. Because it is located in Florida, WTS has experience finding treatment solutions for brackish well water considered unusable for golf course irrigation. The solution for Spirit Hollow, based on its daily irrigation requirements, was a 500,000 gpd reverse osmosis (RO) system.
Last winter, Spirit Hollow’s superintendent oversaw construction of a water treatment plant conveniently located close to both the water well and freshwater lake that would provide storage for the RO permeate. The RO system, manufactured by Water Management Group Inc., and the auxiliary process equipment supplied by WTS were delivered and installed in April. The auxiliary process equipment consisted of multi-media prefiltration and chemical injection of antiscalant chemical. The multi-media filtration system was necessary because of high turbidity in the feed water and because the well casing was made of steel and had the potential to contribute solid and oxidized iron to the feed water.
The process flow for the water treatment plant is as follows: A level control device, located in the lake, sends a signal to the RO control panel when the level in the lake falls below a set point. The RO panel sends a signal to the well pump to turn on, and well feed water flows to the prefiltration system, the prefilter cartridge system and finally to the RO high-pressure pumps. Along the way, the feed water receives a dose of antiscalant chemical to control precipitation of sparingly soluble salts onto the RO membranes.