Engineering clean water
There is more to proper water sanitation than just adding chlorine.
September, 2006- The introduction of enclosed drinker systems or nipple drinkers is one of the top technologies ever adopted by the poultry industry. There is no question that the transition from open troughs or Plassons to nipple drinkers improved the health and well-being of flocks while improving the efficiency of production. One drawback to the enclosed system, however, is that it leads to the “out of sight, out of mind” syndrome, which can give growers a false sense of security that the water to the birds is safe and wholesome. In other words, many producers believe the enclosed systems totally protect the birds from exposure to harmful micro-organisms as well as prevent disease, and this is simply not true. Water systems that are contaminated with bacteria can develop a bio-film coating on the inside of pipes and drinkers. An established biofilm is 10 to 1,000 times harder to remove and can harbor many types of disease-causing organisms, which can impair flock performance and cost producers money.
The University of Arkansas recently installed a new drinking water system at its broiler research farm. The goal in designing the system was to provide a safe, clean and adequate water supply that provides sanitizing residual to the birds on a continuous basis and, at the same time, eliminates iron build-up in the house filters and in the drinkers that can cause the drinkers to leak.
The key to this water treatment system is a gas chlorination injector. Extensive research and field evaluations have proven chlorine gas to be an effective, easy-to-manage sanitizing option for drinking water. Since chlorine gas can present health hazards when inhaled, it is necessary to design a system that will limit the safety issues. The chlorine gas cylinder is stored in a small garden tool shed that is attached to the outside of the well house. A hose runs the gas into the well room, where the gas is injected into the water supply. Chlorine gas is only injected into the water line under a vacuum. This prevents the release of chlorine gas should the injector break loose from the line. It is recommended that a small spin-down filter be installed prior to the injection point to prevent sediment from clogging the line.
Two gas chlorination systems which work well for poultry farm applications are Regal and AgraChlor, which is provided by Aquatech. After chlorination, a peristaltic pump adds an acidifier, PWT or sodium bisulfate, to lower the pH to below 7 so that the chlorine’s effectiveness as a sanitizer is optimized. Free chlorine levels are checked at the end of the drinking lines and are maintained at 0.5 parts per million to 1.5 parts per million. Rubber tubing is used by the injector to pump from a concentrated solution and the injection rate can be varied. The rubber tubing is the only part of the pump which the acid comes in contact with, so the pump does not require extensive maintenance.
After chlorination, the water is run through a Farm Guard filter. This unique filter looks like traditional water line filters, but it is much larger. It can handle up to 120 gallons per minute and has the capacity of 180 string filters. This filter has been extremely effective in removing oxidized iron and preventing iron from clogging the string filters. Before the Farm Guard filter was added to the water system, the farm manager had to change the house filters every three to five days. Now, with two flocks of 38-day-old birds completed, the string filters in each house have remained clean. Between flocks, the Farm Guard filter can be opened, the pleated filter removed and rinsed before reusing. This filter system is one of the more economical options for removing oxidized minerals such as iron, sulfur and manganese. The Farm Guard filter is manufactured by Parker-Hannafin.
To assure that the four-house research farm has adequate water volume during peak demand, a 5,000 gallon above-ground black, water storage tank was added to the farm’s water system. Evaluations of different water storage tanks showed that black storage tanks grew fewer microorganisms than clear tanks, even when the water was chlorinated before storage in both types of tanks. The clear tanks allow sunlight to neutralize the residual chlorine, which allows algae growth in the tanks.
As part of the farm’s regular cleaning and maintenance program, the water lines are flushed between flocks with ProxyClean, which contains a stabilized 50 percent hydrogen peroxide solution. This product can be pumped straight out of the container into the water lines with a medicator or proportioner. The ProxyClean is left in the lines for up to three days before flushing with the chlorinated water. To insure that the water sanitation program is working properly, water samples are submitted for microbial testing.
By designing a water treatment system that addresses the main contaminant, iron, and provides adequate sanitizing residual to the birds, this farm eliminated one potential area that can ruin flock performance.