Chain of custody of the sample is vital.  Aqua WSC Laboratory uses a three-copy form for documentation.   Call us at 512-581-0705 to receive a Chain of Custody form BEFORE you take your sample.  We will also supply an approved Sample Container for your sample.

It is important that you read the Laboratory Acceptance Policy  before completing the Chain of Custody Form and collecting your sample.

Materials required are a Sample Container and Chain of Custody form, both of which are supplied by Aqua WSC Laboratory.


A.   Sample Site Selection
1.   Faucet must not leak.
2.   Faucet needs to be at least eighteen (18) inches above the ground or floor surface.
3.   Constructed of material capable of being heated with a torch or disinfected with a highly concentrated chlorine solution.
4.   Have an outlet pointed downward.
5.   Not located near vegetation.
6.   Have no attachments (water hose or vacuum breaker).

B.   Sample Collection Techniques
1.   Use sample containers provided by us.
2.   Do not collect sample on windy (>20mph) or rainy days.
3.   Do not rinse the bacteriological sample bottle. The bottles contain a substance that neutralizes the chlorine in the sample.
4.   Sample must be submitted to us for analysis within thirty (30) hours of collection.
5.   Sample can be put on ice after collection and prior to submitting to us. Refrigerate sample if held overnight.

C.   Sample Collection Procedures
1.   Wash hands prior to collecting sample.
2.   Flush the faucet for several minutes.
3.   While the faucet is flushing, fill out the Chain of Custody form.
4.   Collect a sample from the faucet for free/total chlorine residual analysis and document the result on the Chain of Custody form.
5.   If no or a low free/total chlorine residual is detected, do not collect a bacteriological sample from this site. Flush the faucet for a longer period of time and resample for free/total chlorine residual. If free/total chlorine residual is still not detected or low, inquire to the appropriate personnel about chlorination systems problems.
6.   Close the faucet and disinfect the faucet outlet.  Prior to collecting the bacteriological sample, an audible sizzle sound and observing a release of stream from the faucet signifies adequate flaming of the faucet.
7.   Open the faucet so that the stream is approximately the same size as a pencil. (Do not allow the stream to spray.)
8.   Fill the bacteriological sample bottle to over the 100 ml mark, but not to the top. The bottle must contain at least 100 ml to conduct the test.
9.   Take extreme precaution with the bacteriological Sample Bottle. The sterility of the bottle can be easily compromised. Therefore, if the cap of the bottle is loose, discard the bottle. Do not touch the cap, the inside of the bottle or the threads on the cap of the bottle, and allow a slight air gap between the bottle and faucet during sample collection.
10.   Store the sample in a safe place to ensure the integrity of the sample is not compromised. Try to keep the exterior of the bottle as clean as possible.

D.   Filling out the Chain of Custody form
1.   Fill out the Aqua WSC Laboratory Chain of Custody form correctly and completely.
2.   System name, public water system identification number, type of system, and type of sample must be included on the Chain of Custody form. The distribution field must be checked for required monthly samples.
3.   Additionally, the location must be noted for distribution and repeat samples.

Offering NELAC Coliform Analysis – Central Texas