Water quality significantly impacts health. Testing for bacteria is an important step in ensuring the safety of your water supply. This process helps identify contaminants and allows for informed decisions regarding water treatment and consumption.
Why Test Your Water
Bacterial contamination in drinking water poses health risks. Total coliform bacteria indicate water quality, as their presence suggests other harmful organisms could enter the supply. While most coliforms are not directly harmful, some strains, like E. coli, can cause severe illness. For example, E. coli can lead to diarrhea, abdominal cramps, and kidney failure. Other symptoms of waterborne bacterial illness include stomach upset, vomiting, and fever.
Testing is especially advisable for private well owners, who are responsible for their water quality, unlike municipal systems. Test your well water at least once a year for total coliform bacteria. Additional testing is recommended in several situations:
- After events like floods.
- If you notice changes in your water’s taste, odor, or color.
- When moving into a new home.
- After well repairs.
- If unexplained illnesses occur among those drinking the water.
Methods for Testing Water
Testing for bacteria in water can be approached through do-it-yourself (DIY) home kits or professional laboratory analysis. Each method offers distinct advantages and limitations. Selecting the appropriate testing method depends on the desired accuracy and comprehensiveness of the results.
DIY Home Testing Kits
DIY kits typically test for total coliforms and sometimes E. coli, often using a color change after incubation to indicate bacterial presence. These kits offer convenience, providing immediate, preliminary results. They are also relatively affordable and easily accessible for quick screening.
However, DIY kits have limitations in accuracy and scope. They lack the precision of professional tests and may not detect low-level contaminants. Factors like water temperature, lighting, and user technique can affect results, and color-comparison tests are prone to subjective interpretation. These kits also test for a limited number of contaminants, potentially giving a false sense of security.
Professional Lab Testing
Professional laboratory analysis is the most reliable method for comprehensive bacterial water testing. Certified laboratories use precise methods to identify a broader range of contaminants, including specific bacterial species like E. coli. The process involves collecting a water sample according to specific lab instructions and sending it for analysis.
Certified labs adhere to strict standards for personnel and testing methods, ensuring reliable and valid results. This approach provides accurate, comprehensive analysis and expert interpretation. For private well owners, using a state-certified laboratory is recommended for annual testing and when more thorough analysis is needed.
Understanding Your Test Results
Interpreting water test results for bacteria involves understanding terms like “total coliforms” and “E. coli.” Laboratories typically report results as “Present” or “Absent” for these bacterial groups. A “Total Coliform Absent” result indicates no coliform bacteria were detected, suggesting the water is microbiologically safe.
If total coliform bacteria are “Present,” it means these indicator organisms were found. While most coliforms are not disease-causing, their presence suggests a potential contamination pathway and unsanitary conditions. Further testing, often for fecal coliforms or E. coli, is then necessary to determine if the contamination is from fecal matter.
A test result showing E. coli “Present” is a serious finding. E. coli are a subgroup of coliform bacteria found in the intestines of warm-blooded animals, including humans. Their presence indicates recent fecal contamination, posing a significantly increased risk of other disease-causing organisms. Any detection of E. coli means the water is unsafe for consumption without treatment.
Steps After a Positive Test
If water testing indicates the presence of bacteria, particularly E. coli, immediate action is necessary. Stop consuming the contaminated water. Boiling water is a common immediate safety measure, as it effectively kills most harmful bacteria. Using bottled water for drinking, cooking, and brushing teeth is also a safe alternative until the issue is resolved.
Identifying the source of contamination is important for long-term solutions. For private wells, this might involve inspecting the wellhead, casing, and seals for damage, or checking for issues with nearby septic systems or agricultural runoff. Contamination can also occur after heavy rains or floods, washing surface contaminants into the well. Consulting a water quality professional can help pinpoint the entry point.
Several treatment options address bacterial contamination. Shock chlorination, which involves adding a high concentration of chlorine to the well and plumbing, is a widely recommended disinfection method. This process kills bacteria throughout the system, though it may be a temporary fix if the source is ongoing.
Another effective long-term solution is installing a ultraviolet (UV) treatment system, which inactivates bacteria and viruses without adding chemicals. Reverse osmosis and other filtration systems can also remove bacteria. After any treatment, retesting the water is essential to confirm bacterial elimination.