Starting a Phosphate Program

Easy steps to follow to get your phosphate program up and running smoothly.

1) Water Quality

Determine the water characteristics or allow a qualified sales representative to test the water and then recommend a product which will  be most suitable for your water. From the water quality analysis, red/black water, scaling , and corrosive tendencies can be determined. 

2) Implementing a Phosphate Program

Consideration should always be given to injection points of phosphate. In a well system that utilizes chlorine or other strong oxidizers, the phosphate program should be added before the oxidizer. If the well system has aeration and/or filtration, the phosphate program should be added after these processes but before the final chlorination. These processes drive off gases and remove iron by precipitation which means there should be less iron to treat in the final product.    

3) Feed rates

Blended phosphates do a very good job of sequestering divalent compounds and preventing corrosion. Most sequestering and corrosion problems can be handled with 2mg/L or less. Some systems may require initial dosages of up to 6 mg/L to clean distribution lines, but even after cleaning, feed rates can be reduced to below 2 mg/L. With a distribution system that has suffered from “red” water or “black” water stains and complaints, a flushing program should be implemented to clean out the system during start up of the program. This will reduce the number of complaints once the program is in place. Please discuss this procedure with your sales representative.   

5) Testing

Phosphorus exists in most waters naturally, primarily in the form of phosphates. Contributors to phosphorus numbers may be in the form of agricultural run off, chemical, or aquatic life. Orthophosphate is the most simple form of phosphate that can be easily detected with current testing methods. Condensed phosphates or polyphosphates require digestion which means heat and a strong acid are used to break the phosphate chains down to orthophosphate. Raw water samples should be tested for background phosphate. Once the program is in place phosphate tests can determine the concentration of product being fed. The total inorganic phosphate of the finished water minus the raw water phosphate concentration results in the concentration of phosphate being added via the product. The percent phosphate divided into this number gives the concentration of product being fed.   

%Polyphosphates =

 total inorganic phosphate – [Ortho of finished water – Ortho of raw water]  

                                  total inorganic phosphate

%Orthophosphate=

Orthophosphate of finished water – Orthophosphate of raw water

                                total inorganic phosphate]

Please review the procedures for each phosphate test.