Joined: 05/12/2023 11:56 AM EDT
Location: Indiana, SW Michigan
To ensure delivery of the most VALID WATER RESULTS possible to your client, it is essential to follow proper protocol when both collecting and shipping samples to the lab.
*EPA protocol (reference below) states to remove aerators and screens, make sure faucet is clean, run water for 5-6 min prior to collecting the sample.
*For the LEAD part of your sample collection DO NOT REMOVE AERATOR or screens and do not run the water ahead of time. Open faucet and collect the water out of the tap. Then proceed to the next steps for your other bottles (bacteria and nitrate bottles) *for a true first draw lead test the water should have been undisturbed in the system 6 hours prior to collection.
Removing aerators can be tricky with the newer pull out faucets so you must be careful to hold the faucet while still being able to collect the water and not allowing the flexible faucet to suck back in while at the same time being sure not to compromise touching the bacteria bottle.
Wearing gloves, cleaning off the tip with alcohol or clorox wipe ensures to not contaminate a sample.
Run the water for 5-6 min.
DO NOT put cap down on the counter or touch the inside rim as this can contaminate a sample. Hold cap in one hand and collection bottle in the other hand when filling the bottle. (Super tricky when also holding a pull out faucet, but it is successfully possible, I have done it a million times)
Samples should be on ice in a cooler FROM COLLECTION UNTIL THEY REACH THE LAB.
Samples need to be shipped so the lab receives them within 30 hours of the time collected. This most likely means shipping NEXT DAY MORNING arrival to the lab. If your samples arrive at the lab more than 30 hours after you collected water, your sample is out of hold time and NOT VALID.
WHY IS THIS IMPORTANT? If the lab processes your sample when out of hold time, bacteria becomes less viable causing a FALSE NEGATIVE. In the case of nitrates/nitrates the opposite happens after hold time has expired causing a FALSE POSITIVE from oxygen atoms swapping resulting in instability. However, when it comes to metals such as LEAD, there is a two week hold time so you are most likely good there.
The above post was written assuming most home inspectors are collecting FHA samples which include bacteria (total coliform/ecoli) nitrates/nitrites and lead.