This operating procedure was developed by Dr Susan Watkins of the University of Arkansas for Aviagen. You can access it on the Aviagen Information Library: AviaTech – Water Line Sanitation (PDF, 311KB).

Step 1—Analyse water

Analyse the water for any scale-causing minerals: carbonates or bicarbonates of calcium, magnesium, iron and manganese.

If the water contains more than 90ppm combined calcium and magnesium, 0.3ppm iron or 0.05ppm manganese, you will need to include a descaler or an acid treatment in your cleaning program. These products will dissolve the mineral deposits in water lines and fittings.

Step 2—Select sanitiser

Choose a sanitiser that can effectively dissolve any biofilm or slime in the system. Some of the best products for this job are concentrated hydrogen peroxide, chlorine and chlorine dioxide solutions. Before using any strong cleaners, make sure standpipes are working properly so air pressure build-up in the lines will be released. Consult equipment suppliers before using products to prevent unnecessary damage.

Step 3—Prepare the distribution system for sanitising

For best results, use sanitising products at the strongest concentration recommended on the label. Most proportioners (a device for securing proportions in a mixture or a chemical dosing device) will only allow concentrations between 0.8 and 1.6% of the original material. If you need to use higher concentrations, it is better to mix the stock solution in a large tank and then distribute without the use of a proportioner. For example, if a 3% solution is required, mix three volumes of the cleaner with 97 volumes of water for the final solution.

An excellent sanitising solution can be made up by using a 35% hydrogen peroxide solution. Mix this as described for a 3% solution.

Step 4—Clean the lines

It should take 30–38L of water to fill and clean 30m of 20mm water line. If the building is 150m long and has two water lines, you should make up a minimum of 378L of sanitising solution. Water lines should be designed so that they can be opened to drain completely when the cleaning is complete.

Follow these steps to clean the water lines:

1. Open water lines, so they drain completely.
2. Begin pumping the cleaner or sanitiser through the water lines.
3. Watch the water as it leaves the drain line for signs of the product such as foaming or suds.
4. Once water lines are filled with the cleaner, close the tap and leave the product in the lines for as long as the manufacturer recommends (over 24 hours if possible).
5. Flush cleaner from the water lines after the holding period. Water used to flush the lines should contain the level of sanitiser normally used in the drinking water for the birds.
6. After cleaning, sanitising and flushing the system, the water supply should be fresh and chlorinated (3–5ppm in the drinker furthest from the source). If using an ORP meter, the reading should be a minimum of 650mV.
7. Water lines from the water well to the poultry buildings should also be cleaned and sanitised between flocks. It is best not to flush these outside water lines through the water lines inside the buildings. Connect a water hose to the medicator faucet to drain the outside lines.

Step 5—Remove mineral build-up

After lines are cleaned, descaler or acid products can be used to remove the mineral build-up. Use products according to the manufacturer’s recommendation. One product that can be used for this is citric acid.

Follow these steps:

1. Make a stock solution by mixing 1–2 packs of citric acid (1 pack contains approximately 210g in 23.8 litres of water). Proportion this stock solution at 7.5 grams per litre (0.8% or 1:128). Fill water lines and let stand for 24 hours. It is critical that the water pH is below 5 for optimum scale removal.
2. Empty the water lines. Mix a stock solution containing 62–93mL of 5% bleach per litre. Then refill the lines with clean water containing this stock solution proportioned at 7.8mL per litre (0.8% or 1:128). Leave in the water lines for 4 hours. This concentration of chlorine will kill any residual bacteria and further remove biofilm residue.
3. Perform a final flush of the water lines, use water with a normal drinking water level of sanitiser (normal level of sanitiser equates to 31mL of 5% bleach per litre, proportion this stock solution at 7.8mL per litre). Continue flushing until the water in the lines contains no more than 5ppm of chlorine when tested.

Step 6—Keep the system clean

Once the system has been sanitised, it is important to keep it clean. Develop a good daily water sanitisation program for your birds. The ideal water line sanitation program should include injecting both a sanitiser and an acid. It is important to note that this procedure requires two proportioners or injectors, since acids and bleach should never be mixed in the same stock solution.

If only one proportioner or injector is available, then inject bleach (concentration of 5%) at a rate of 31–46mL per litre stock solution; proportion at 7.8mL per litre of drinking water.

The objective is to provide a clean source of drinking water with a continuous level of chlorine at 3–5ppm at the end of the building furthest from the proportioner.

Other sanitisers

Ozone (O₃) is a very effective bactericide, virucide and chemical oxidant. Ozone will react with iron and manganese, making both more easily removable by filtration. It also works independent of pH, and it can inactivate chlorine if they are used simultaneously. However, ozone is a point of contact sanitiser that dissipates rapidly providing no sanitising residual in the water system.

Chlorine dioxide (ClO₂) is making its way onto the market as a poultry drinking water sanitiser, partly because new chlorine dioxide generation methods have resolved the application of chlorine dioxide. Chlorine dioxide is as effective as chlorine, as a bactericide and even more effective as a virucide, and is also superior to chlorine for the removal of iron and manganese. It is not impacted by pH.

Final notes

1. Do not use acid as the sole method of water treatment since acids alone can cause bacterial or fungal growth in water systems.
2. Hydrogen peroxide is very aggressive, and handling requires extreme care. A test on any components should be carried out before the implementation of such a chemical. It is important to follow the handling and usage instructions very closely to prevent damage to people and equipment.
3. Hydrogen peroxide is gaining popularity as a water sanitiser. pH and bicarbonate alkalinity both play a major role in the effectiveness of hydrogen peroxide. Hydrogen peroxide can be stored onsite, but it will deteriorate over time. It is a strong oxidant, but it does not provide any lasting residual. A 50% hydrogen peroxide product stabilised with silver nitrate is proving to be a very effective sanitiser and line cleaner that does not damage water lines.
4. When administering other products to your birds, it is a good idea to stop the inclusion of chlorine (and other sanitisers) in the drinking water. Chlorine will inactivate vaccines and reduce the effectiveness of some medications. Resume use of chlorine and/or other sanitisers after treatment is finished.
5. Local regulations can govern water line sanitation. Please check with local authorities and always follow the manufacturers’ instructions.