Public Health Laboratory Services

Effective immediately

The Public Health Laboratory no longer tests the Dermacentor species ticks for the presence of Borrelia burgdorferi. Dermacentor variabilis, also known as the American dog tick, is the most common species found in California.

Studies show that only the Ixodes species ticks can infect a host with B. burgdorferi upon blood-feeding. Ixodes pacificus, also known as the western blacklegged tick, is the most common species found in California. The Public Health Laboratory will continue testing the Ixodes species ticks for B. burgdorferi.

The laboratory will still accept and identify the Dermacentor species ticks. The fee for identification and/or testing will remain the same ($45), regardless of the type of the tick submitted. No refunds will be issued.

The Public Health Laboratory offers bacterial testing for well-water safety and tick identification for Lyme disease upon request.

Note: Ticks are only accepted by mail. Send to:

Napa-Solano-Yolo-Marin County Public Health Laboratory

ATTN: TICK TESTING

2201 Courage Drive, MS 9-200
Fairfield, CA 94533

Fees: Please make checks out to: Public Health Laboratory. Or, use the online Tick Payment Portal.

You will still need to complete a laboratory requisition with your submission. The receipt number generated by the online portal must be included on the requisition. Links to the online payment portals and requisition forms appear below:

Tick Payment Portal
Water Testing Payment Portal
Requisition Forms

Tick Identification Fee*: $45.00

See portal for well water testing prices. There is a fee schedule with a list of options available via the well water testing payment portal link above.

*Fees are subject to change without prior notice.

Tick Removal Procedure:

If possible, have someone else remove the tick from you.
Use tweezers or forceps rather than your fingers.
If you must touch tick use a tissue or gloves to protect your hand.
Grasp the tick's mouthparts as close to the skin as possible.
Gently pull the tick straight out, steadily and firmly. Do not twist or jerk the tick.
If mouthparts of the tick break off and remain in your skin, consult your physician.

Tick Collection Procedure:

Place tick into clean capped container or a zip-lock plastic bag. Place a piece of cotton or tissue moistened with tap water into the container with the tick. (Note: do not use alcohol, formalin or other liquids. Do not stick tick to scotch tape. These materials make testing for the Lyme organism unsatisfactory.)
Mail tick to Napa-Solano-Yolo-Marin Public Health Laboratory, ATTN: Tick Testing at 2201 Courage Drive MS 9-200, Fairfield, CA 94533.
Complete a laboratory form and supply the following information:
- Name, address and birth date of person bitten.
- Location of the bite (arm, neck, etc.)
- Date tick removed.
- Estimated duration of time tick was attached (i.e. 4 hrs, 24 hrs, etc.)
- Geographical location (what city, park, etc.) tick was obtained.
- Phone number, name and address of person to receive report.
- Any obvious symptoms.

Water Testing Information:

Marin County Public Health helps facilitate two types of water testing:

Bacteriology (e. coli)
Nitrates (from agricultural runoff)

To test water on private property for either bacteriology or nitrates, it is necessary to pick up specially prepared water bottles at Marin County Public Health Department, located at 3240 Kerner Blvd, San Rafael. Upon arrival, press the white doorbell button to the right of the front doors labeled “Water Sample Drop Off” and wait for County staff to arrive. Staff will provide the number and type of bottle(s) needed.

Drop off days and times:

Bacteriology Samples: Beginning April 1, 2025: Monday - Thursday, 9:00 AM – 12:00 PM and 1:00-1:30 PM

Nitrate Samples - Tuesdays only, during the same hours as above.

Water sample drop-off is at the same location as where the bottles are picked up. Please press the doorbell for staff to retrieve your samples.

Water samples must be kept refrigerated. Please ensure the samples remain in a cooler with ice packs when bringing them to Public Health.

Please drop off your water samples the same day you collect them as they are time sensitive. Please complete the lab requisition form that is in the bag with the bottle prior to drop off.

For recreational beach water testing, please perform sampling after 8:30 am to ensure there is enough time for the samples to be couriered to the lab and tested before the 8-hour sample expiration.

Please visit the NSYM Public Health Lab for prices. Payment can be made online or by submitting a check with the bottles: Water Testing Fee Schedule