Interpreting Water Results

By Dr. Susan Watkins

Interpreting Your Microbial Analysis

This information sheet is to help you to interpret the results of your recent microbial analysis of poultry drinking water and/or well water.  It consists of excerpts from the paper “Water Quality and Sanitation” by Dr. Susan Watkins from the University of Arkansas.  If you would like the paper in its entirety, please contact us at (479) 575-8428.

Bacteria TEst

The established guidelines for water quality for poultry are outlined in Table 1. Note that CFU/ml means colony-forming units of bacteria/milliliter of water, and mg/l is also the same as parts per million or ppm. The microbial or bacterial test results you receive from this lab are TPC or Total Plate Count of aerobic (oxygen loving) bacteria as measured by CFU/ml.  These results do not indicate whether the bacteria present is harmful or harmless but what it can tell you is if the system is dirty and therefore at risk for the presence of harmful bacteria.  If the total plate count or TPC level is 1000 CFU/ml or less then the water supply is considered acceptable.  However, it is very reasonable to have water tests show 0 CFU/ml even from the end of the drinker line.  The closer your water sample results are to 0 CFU/ml the better your water supply is for the modern commercial chicken or turkey.  Should the test results be greater than 10,000 CFU/ml, it is strongly recommended that the water system be thoroughly cleaned between flocks with an approved cleaner and then a daily water sanitation program implemented.  Chlorine is the cheapest water sanitizer available and works well but other products such as chlorine dioxide and hydrogen peroxide are also available and used successfully.  Target levels of chlorine are 3-5 ppm.  Target levels of chlorine dioxide are 0.8 ppm and target levels of hydrogen peroxide are 25-50 ppm in the drinking water.

If your water test is performed by the Department of Health, the results will be total coliforms.  Coliforms are a good indicator organism that lets us know if a water supply has been contaminated by livestock (runoff from concentrated animal production areas) or human waste (failed septic system).  Should your water supply contain more than 50 CFU/ml coliforms it is definitely a good idea to treat the water supply possibly with shock chorination.  In addition, look for possible sources of contamination and correct the problem to prevent recontamination.   Never assume that water remains good through poultry house water systems.  When in doubt, test the water at the source and at the end of the line.  Results from previous water tests (Table 2) show just how dramatically water quality can change even over the course of a few hundred feet.

Use the following guidelines to determine when water supplies should be tested:

•         Noticeable change in color, odor or taste

•         Flooding has occurred near well

•         Person or animal becomes sick from waterborne disease

•         Maintenance on water supply system

•         Persistent poor performance

•         Loss of pressure in water system

MINERAL TESTS

There is no such thing as pure water in drinking water supplies.  All drinking water has some amount of minerals dissolved in it.  The majority of the time, these dissolved minerals are well within acceptable ranges but unfortunately  there are many cases of contaminants that are not within desired levels which results in the following issues:

1. Poor performance
2. Equipment failure or damage
3. Presence of harmful bacteria or fungal slime (some minerals can act as a food supply for these).

One way to understand how much is a ppm is consider one gallon of sugar dissolved into a million gallons of water. That would give 1 ppm of sugar. Although parts per million (ppm) of anything seems quite small, remember, the birds already receive a balanced diet and if they are also receiving high levels of such nutrients as salt in the water, in the form of sodium and chloride ions, then over time the birds may exhibit poor performance because they just have more than their systems can handle. In addition, water contaminants can also impact how nipple drinkers work. Even a fine buildup of mineral residue on seals or rims could be all that is necessary to limit water flow and thus result in less than adequate consumption for optimum bird growth and feed conversion.

Conclusion

In conclusion, water is the most essential nutrient birds receive, yet the quality of bird drinking water is often taken for granted. Providing flocks with a clean, wholesome supply can make a difference in performance. Should water be a suspect for flock problems, make arrangements to have water tested for total bacteria numbers as well as for mineral content. While total aerobic plate count won’t tell exactly what is in the water, it is an indicator of excessive levels of bacteria that should be addressed. By promoting a regular water sanitation program on farm, producers can prevent environments in water systems that could lead to poor bird performance.

 

Contaminant, mineral or ion	Levels considered average	Maximum Acceptable Level	Comments
Bacteria Total Bacteria (TPC) CFU/ml Total Coliforms Fecal Coliforms	0 CFU/ml 0 CFU/ml 0CFU/ml	1000 CFU/ml 50 CFU/ml 0 CFU/ml	Total Bacteria is used as an indicator of system cleanliness, high numbers do not necessarily mean the bacteria present is harmful but it does mean that the system is capable of harboring pathogenic organisms. High bacteria levels can impact taste of water resulting in reduced consumption by birds Shock well then implement sanitation program such as gas chlorine, hydrogen peroxide or other sanitizers. Maintain a residual   Presence of any fecal coliform means water is unfit for consumption by poultry or humans
pH	6.5-7.8	5-8	pH below 5 can be harmful to drinker equipment-causing corrosion to metal components with long term exposure pH above 8- impacts effectiveness of most water sanitizers and if high pH is also associated with high alkalinity, may result in reduced water consumption in poultry due to “bitter” taste. If pH is lower than 5 soda ash or caustic soda injection will raise pH. If pH is high acid injection will be required.
Total Hardness	60-180 mg/l	110 mg/l	Hardness can also be determined by adding the Calcium and Magnesium content, Hardness causes scale which can reduce pipe volume and cause drinkers to be hard to trigger or leak Softeners can remove compensated hardness up to a practical limit of 100 gpg or 1710 ppm /mg/l If the hardness is above 30 gpg or the sodium to hardness ratio is greater than 33% then the sodium level will be high after softening and reverse osmosis may be required .Phosphate injection will sequester the hardness.
Natural Elements
Calcium (Ca)	60 mg/l		No upper limit for calcium, birds very tolerant of calcium but if values above 110 mg/l may require water softener, polyphosphates or acidifier to prevent scaling
Magnesium (Mg)	14 mg/l	125 mg/l	Higher levels of Mg may cause flushing due to laxative effect particularly if high sulfate present
Iron (Fe)	.2 mg/l	.3 mg/l	Birds tolerant of iron metallic taste but high iron causes leaking drinkers and promotes the growth of E coli and pseudomonas , Treatment includes oxidation with chlorine, chlorine dioxide or ozone and then filtration
Manganese (Mn)	.01 mg/l	.05 mg/l	Can result in black grainy residue on filters and in drinkers, Treatment includes oxidation with chlorine, chlorine dioxide or ozone then filtration, green sand filtration and softeners will remove Mn make sure you pay close attention to pH when deciding what method to use.
Chloride (Cl)	50 mg/l	150 mg/l	When combined with high sodium levels, creates salty water that can act as a laxative causing flushing, also, salty water can promote the growth of enteroccoci organisms that can lead to enteric issues Treatment- Reverse Osmosis, anion exchange resin, lower dietary salt level, blend with non-saline water, Keep water clean and use daily sanitizers such as hydrogen peroxide or iodine to prevent microbial growth
Sodium (Na)	50 mg/l	150 mg/l	When combined with high chloride levels, creates salty water that can act as a laxative causing flushing, also, salty water can promote the growth of enteroccoci organisms that can lead to enteric issues Treatment- Reverse Osmosis, lower dietary salt level, blend with non-saline water, Keep water clean and use daily sanitizers such as hydrogen peroxide or iodine to prevent microbial growth
Sulfates (SO4)	15-40 mg/l	200 mg/l	Sulfates can cause flushing in birds. If rotten egg odor present, then bacteria producing hydrogen sulfide are present and system will require shock chlorination plus establishment of good daily water sanitation program, sulfates can be removed by reverse osmosis or anion resin. If H2S is present (the rotten egg smell) than aerating water into a holding tank, treatment with sanitizers then filtration
Nitrates	1-5 mg/l	25 mg/l	High nitrate levels can result in poor growth and feed conversions. Plus presence of nitrates may indicate fecal contamination so also test for bacteria Can be removed with Reverse Osmosis Or anion exchange resin.
Lead	0 mg/1	.014 mg/l	Long term exposure can cause weak bones and fertility problems in breeders and turkeys. reverse osmosis ,softener or activated carbon will greatly reduce the lead
Copper	.002 mg/l	0.6 mg/l
Zinc		1.5 mg/l