While visiting several golf facilities during the previous two weeks, a question was asked about adding new sand to existing bunkers. In both cases, the bunkers contained seven-year-old sand that is no longer available. As expected, the sand is thin in the bunkers and golfers feel the bunkers are too firm. For your reference, the desired depth for bunker sand is approximately 4-6 inches on the base of the bunker, and 2-3 inches on the face.
The question is can new sand be added that is compatible in color and physical characteristics to the existing sand? The answer is a bit more complicated than a simple yes or no. How should a course proceed if they find themselves in a similar scenario?
First, collect sand samples from several of the existing bunkers. The sand samples should be sent to an accredited soil physical testing laboratory for analysis. If the physical characteristics of the existing sand are within the generally accepted guidelines for bunker sands, then proceed to the next paragraph. However, if the existing bunker sand has become contaminated and no longer conforms to the guidelines for bunker sands, the existing sand will likely need to be replaced with new sand that will perform up to expectations.
Assuming the existing sand has retained desirable physical characteristics, submit 2-3 samples of new sands (that are locally available and come from a reliable source) to an accredited soil physical testing laboratory for analysis. Discuss the project with a representative from the soil physical testing laboratory and have them mix the new sand with the existing material in various ratios (for example, 1:1, 1:2 and 2:1). Choose a mixture that will yield sand that exhibits good physical characteristics and desired color (the USGA has a bunker sand selection guide: How to Select the Best Sand for Bunkers). For a more technical guide to selecting bunker sands, click on the following article: (Physical Analysis of Sands for Golf Course Bunker Use).
Once the new sand arrives, the existing sand should be piled into the center of a bunker and thoroughly mixed with the new sand using a shovel, backhoe or skid steer. Once mixed, distribute the sand over the entire bunker. If the new sand is placed on top of the existing sand without mixing, a layer will likely develop that may negatively impact cosmetics and playability.
Please don’t hesitate to contact the southwest regional Green Section office if you have any further questions on this procedure or any other golf course management concern.
Source: Brian Whitlark (firstname.lastname@example.org)
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