AARST MW-RN Companion Guidance 2020 FOR THE FIELD 1 FOR THE FIELD This table is intended to add clarity to a few important fundamentals BEFORE YOU COLLECT WATER SAMPLES Section 3 Section 3 requirements and Exhibit 1 “Example — Water Sample Collection Form” stress the importance of documenting details of water collection events that will be needed during laboratory analysis and for test reports. Section 3 and 4 Sections 3 and 4 provide critical details for obtaining valid water samples. The goal is to collect a water sample that is from the source of the water, rather than water that can be stagnant within a buildings water pipes or holding tanks. Such measurements identify radon concentrations that primarily pose a hazard when released into the air within a building. While other hazards may exist, use of water that is releasing radon into the indoor air can increase the chances of radon-induce lung cancer. Section 3, 4 and 5 Sections 3, 4 and 5 additionally speak to another critical detail for obtaining valid water samples. The goal is to obtain samples of water that are not aerated. The care described in each method and procedure entails ensuring that the water sample is the same as the source of water before it comes in contact with air. Any event where the water is splashed or turbulent where water comes in contact with air will release radon from the water and provide a false test result. Critical procedures, such as overflowing funnels or bowls with faucet ends submerged, speak to required care needed for obtaining a valid sample that does not include aerated water. In this regard: It is also important to remember that even bubbles larger than 1 mm (1/16 inch) in diameter, occurring simply during efforts to close bottles, can adversely impact reliability of the test result. IMMEDIATELY AFTER COLLECTING WATER SAMPLES Section 6 Section 6 provides critical guidance for handling samples in the field. Responsible care is needed to ensure timely analysis of water samples. Delays and exposures to heat, which can cause bubbles to form, could adversely impact reliability of the test. TEST RESULTS Sections 7 and 8 Sections 7 and 8 provides action levels and mitigation guidance along with requirements regarding: 1. Test results that disagree; 2. Post-mitigation testing; and 3. Test report requirements PROFESSIONAL REQUIREMENTS Sections 9-14 Sections 9 – 14 elaborate in detail on requirements for professional services that include field professionals and analysis procedures for each measurement method.