Water Lab
Important Notice
Starting January 2026, Thurston County water lab customers must drop off water samples at our Public Health & Social Services Building, located at 412 Lilly Rd. NE, Olympia (across the street from Providence St. Peter's Hospital). The Atrium location at 3000 Pacific Ave SE., Olympia, will no longer accept water samples starting January 2026. Bottle pick-up and the option to pre-pay will still be available at the Atrium.
Also starting in January 2026, Mason County water samples will be picked up on Tuesdays ONLY at 4:00pm.
Water Quality Lab
The water quality lab carries out bacterial analyses of drinking water, surface water, suspected sewage discharges, treatment plant effluent, marine water, and soils. The lab also performs nitrate analyses of drinking water.
Water Testing
Drinking water may contain contaminants that could pose a human health concern. An important way to ensure that drinking water quality is safe for human consumption is to test the water. Testing can help to determine: 1) if a contaminant is present, and 2) if present, whether the level of concentration is high enough for concern.
Drinking Water
- $32 Presence or Absence of Total Coliforms and E. coli
- $32 Nitrate
Bacteria Count for Drinking Water or Non-potable Water
- $40 (Total coliforms and E. coli, Fecal Coliforms, or Enterococci)
Hours of Operation
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Bacteria Samples
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Nitrate Samples
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Lab does not accept bacteriological samples on legal holidays or on the weekday before a legal holiday due to the 2-day processing time.
Bottle Pick Up and Sample Drop Off Information
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The Atrium, 3000 Pacific Avenue SE, Suite 225 |
(360)-867-2685 |
BOTTLE PICK UP: Mon – Fri, 8am-4pm NOTE: Starting January 2026, sample drop-off at the Atrium will end. |
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Public Health & Social Services Building, 412 Lilly Road NE |
(360) 867-2631 |
BOTTLE PICK UP: Mon – Fri, 9am-4pm External Water Sample Mailbox Mon-Wed, 8am-5pm and Thurs. 8am-12:30pm for Coliform Bacteria and Mon. 2pm-5pm & Tues. 8am-5pm for Nitrate. |
If you wish to attach payment with the water sample(s) please make checks payable to Thurston County Environmental Health (TCEH) and rubber band to sample with lab slip. Please check the current fee schedule for total fees due.
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Mason Health Department, 415 N 6th Street (downtown Shelton) |
360-427-9670 ext. 400 |
BOTTLE PICK UP: Mon – Fri, 8am-4pm NOTE: Starting January 2026, water sample pick up will be on Tuesdays ONLY at 4:00pm. |
Note: Samples can also be brought to the Thurston County Water Laboratory at 412 Lilly Rd. NE, Olympia WA. Coliform bacteria Mon-Wed 9am-5pm; Thursday 8am-12:30pm and Nitrate Monday after 2pm and Tuesdays 8am-5pm
| Rainier Town Hall, 102 Rochester St W | 360-446-2636 or 360-446-2265 | BOTTLE PICK UP: Mon – Thurs, 8am-5pm SAMPLE DROP OFF: Tuesday ONLY, 8am-12pm for Coliform Bacteria and for Nitrate. |
| Tenino City Hall, 149 S. Hodgden | 360-264-2368 | BOTTLE PICK UP: Tues– Fri, 8am-4pm SAMPLE DROP OFF: Tuesday ONLY, 8am-12pm for Coliform Bacteria and for Nitrate. |
| Rochester (R.O.O.F), 10140 Highway 12 | 360-273-6375 | BOTTLE PICK UP: Mon – Fri, 9:30am-5:30pm SAMPLE DROP OFF: Tuesday ONLY, 9:30am-12pm for Coliform Bacteria and for Nitrate. |
| Yelm Public Works, 901 Rhoton Rd SE | 360-458-3244 or 360-458-8406 | BOTTLE PICK UP: Mon – Fri, 8am-5pm SAMPLE DROP OFF: Tuesday ONLY, 8am-12pm for Coliform Bacteria and for Nitrate. |
FAQs
Follow these directions for disinfecting your well if your water has coliform bacteria in it. This disinfection process treats only biological contaminants, not chemical or mineral contaminants. Disinfecting Your Well
1. Flush the System.
- If your water is cloudy, let the water run for 10-15 minutes before disinfecting.
2. Chlorinate the well.
- Use household bleach which typically has a chlorine concentration of 6%. Do not use “ultra” concentrated bleach or bleach products with additives or perfumes.
- The amount of bleach to use is according to the chart on page 2. If you have problems calculating the amount of bleach to use, contact Thurston County Environmental Health.
- Mix bleach in a bucket of water. Remove well cap, plug, or vent (see diagrams on page 2); using a funnel, pour the bleach into your well.
3. Mix the bleach with the well water.
- Attach a hose to the nearest outside faucet and allow the water to run onto the ground for 1-2 minutes until you smell chlorine. Then place the hose in the hole where you poured the bleach, allow the water to run back into the well for 15-20 minutes.
- Remove the hose and replace the well cap, plug, or vent.
4. Chlorinate the lines.
- Turn on each tap attached to the well (kitchen, bathroom, outdoor spigot, etc.), starting with the nearest tap to the well, and let the water run until you smell bleach, turn off and then go to the next tap.
- Turn off electricity to the pump and let sit overnight.
5. Flush the chlorinated water out of the system.
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Choose any outdoor spigot and let the water run onto the ground, away from your septic system (also keep water flow from going into creeks, streams, or where fish or vegetation can be harmed), until you no longer smell bleach. This empties the bleach from the well.
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Turn on each faucet inside the house until you no longer smell bleach.
Once the system has been flushed of all bleach, the water can be used for laundry and bathing, but you should not yet use it for drinking, brushing teeth, making ice or preparing food.
Wait 3-4 days after flushing the bleach out to collect coliform bacteria samples. You may need to repeat this process several times before coliform test results are “satisfactory”. Also, be aware that the bleach may disturb built-up minerals in your pipes and temporarily discolor your water. This discoloration should disappear once the bleach is flushed out of your system.
For more information, call Thurston County Environmental Health Division at (360) 867-2673.
Stop drinking the water. Have your water tested for coliform bacteria, see Testing Your Well for more information. Contact our office at 360-867-2631.
If you know the name of the water system, you can find that information by searching the DOH Public Water System Database. Or you can call our office at 360-867-2673.
Contact our department or email us at environmental_health@co.thurston.wa.us if you have additional questions.
| Water Quality Lab | 360-867-2631 | General Drinking Water & Wells | 360-867-2673 | Public Water Systems | 360-867-2630 |