Environmental Health Department
4520 Reading Rd., Ste. A-800
Rosenberg, Tx 77471
O:281-342-7469 | Fax: 281342-5572
Water Sample Instructions
Regardless if a water well is new or existing, water sampling must be done with special
consideration to obtain a good water sample and avoid additional contamination.
The water well can not be submerged in floodwaters. Well needs to be disinfected before testing (see step 12 for instructions).
Please read this document completely, as it outlines the correct procedure for taking a water sample.
1. Obtain an approved sterile sampling container and current Water Sample Form.
These may be picked up from our office or the City of Houston Water & Dairy
Laboratory. Do not use jars or other containers from home or other sources.
Use approved water sample containers only.
2. Select a cold water faucet or tap nearest the well. Most wells have a faucet located on
the water line exiting the tank. Samples should come directly from the well or the tank.
If a water softening or filtration system is connected to the water source, the water sample
should be taken from a tap or faucet prior to either of these types of system.
3. Remove anything attached to the faucet. Hoses, aerators, or anything else attached to
the sample faucet may cause contamination.
4. You want fresh well water in your sample. Turn on the tap or faucet. Let it run for at
least ten minutes so that the well pump is activated and you obtain a fresh supply of water
from the well.
5. Do not get your hands dirty. While the water source is running, wash your hands
thoroughly with soap and water. Do not handle animals, place anything in your mouth,
or do anything that might contaminate your hands and cause the water sample to become
6. Turn off the faucet and sanitize it. If the faucet is metal, it can be done by heating it
with a cigarette lighter or a propane torch. Heat the faucet until it is dry. If the sample is
to be taken from a plastic or chrome faucet such as your kitchen sink, do not heat it.
Swab inside and around the opening of the faucet with a cotton ball soaked in rubbing
alcohol or use a spray bottle containing a water/bleach mixture.
7. Collect the sample. Turn the faucet on to a slow trickle. Carefully open the water bottle
making sure not to touch the inside the cap or the bottle threads. Avoid breathing into the
bottle. Fill the bottle to the neck and secure the cap. While filling the bottle, do not lose
or rinse out the white substance inside the bottle. This is sodium thiosulfate. Its purpose
is to neutralize any chlorine in the water sample.
8. Protect the sample. Keep the sample out of direct sunlight and away from heat. Until
you are ready to bring the sample in, keep the sample cool, not frozen, in a refrigerator or
cooler. After you take the sample, you have twenty-eight (28) hours to deliver it to the
9. Fill out a sample form. Complete the form using black ink only. Make sure the
information is complete. If you have a Public Water System, make sure to include the
ID number in the space provided on the form. If you have a chlorinated well, make sure
to test the chlorine residual and include that information in the space provided on the
form. After completion the form, include a check or money order for $16.50 payable to
the City of Houston. No cash. Wrap the form and payment around the bottle and secure
it with a rubber band. If you have an account with the Houston Lab, include your
account number on the form or the sample may not be processed.
10. Get the sample to the lab. As a courtesy, this office will courier water samples
submitted on Wednesdays between the hours of 8:00am and noon. You should receive
the laboratory report within 7-10 days. Should your report not arrive in two weeks, you
may contact the laboratory by telephone. The following information will be required to
locate the results: (1) the date the sample was brought in (2) the county in which the
sample was collected and (3) the return address exactly as the form was completed.
Should you need results for a real estate closing, please fill out the form for FAXING
RESULTS which can be obtained in our office.
11. What the laboratory report means. If coliform organisms are not found, the water is
bacteriologically safe to drink. If coliform organisms are found, the water contains
bacteria commonly present in sewage which might include typhoid or other disease
producing bacteria. Contaminated water should not be used for drinking or washing
teeth, wounds, or vegetables which are to be eaten raw. Use bottled water until the water
supply is decontaminated. Contaminated water may be boiled for a minimum of 20
minutes or may be treated with 6 to 10 drops of household chlorine bleach per gallon at
least 30 minutes before use.
12. How to treat a contaminated well. Obtain 1 gallon of chlorine bleach. Dilute it with 5
gallons of water and pour it directly into the well casing. Connect a garden hose to a
faucet near the well and let it flow into the well casing until the odor of bleach is detected
from the hose. Shut off that faucet and open all other cold water faucets until the bleach
odor is detected from each faucet. Then open all hot water faucets to allow the bleach
into the cold water line serving the water heater. Let the bleach remain in the well and
piping for at least 4 hours, preferably overnight. Then open one exterior faucet and let
the water run until the bleach odor is gone. Next flush each cold water faucet similarly.
Wait 3 days before taking a new sample to the laboratory. It is not unusual repeat this
treatment 3 or 4 times before no contamination is found by laboratory tests. All wells
should be tested for contamination at least twice each year.
Sterile sample bottles can be picked up starting September 5, 2017 at 4520 Reading Rd., Ste. A-800, Rosenberg, Tx 77471 until further notice.
Water samples are only tested for the presence of fecal coliform bacteria. If you desire
your water tested for other substances, contact the Texas Commission of Environmental
Quality at (713) 767-3500 for further information.