Water Wells and Septic Systems after Wildfire

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Mark Septic System and Well Locations before Debris cleanup begins

This process is a critical measure to help preserve the property’s septic system and to avoid costly replacements or repairs. Even the removal of small amounts of soil from leach fields can result in the area no longer being a feasible leach field. It is imperative that areas be marked and the location information be shared with the debris removal contractor.

Before debris clean up starts, property owners should clearly and visibly mark the location of their septic systems or systems associated with their property including the following:

  • Septic tanks
  • Pump tanks
  • Pretreatment units
  • Electrical components
  • Distribution boxes (if location is known)
  • Both the existing primary leach field area and (if known) the expansion leach field areas.
  • Any transmission lines from the septic tanks, pump tanks, pretreatment units to the leach field.
  • The location of any water wells.
  • The location of any water well lines from the water well to the buildings.

If property owners do not know the location of their system, they can come into the Permit Center to look for property records. If there are no records available, customers can be provided with a list of certified contractors in the area who can identify the location of the properties septic system.

Inspecting Wells and Septic Systems after Wildfire

As an owner of a septic system or private domestic water well that may be damaged by a wildfire, you may have some concerns about fire related impacts to your septic and well water systems.

Sonoma County Environmental Health (EH) recommends the well owner perform a visual inspection of their well and water system, including the piping and plumbing that provide water to and throughout your home. Items that you should check include:

  • Damaged and melted or exposed electrical wiring
  • Damaged and melted PVC casing, liner or pipe
  • Damaged well houses, pressure tanks and equipment such as chlorinators, water treatment equipment and electronic controls
  • Damage to pressure tanks which could have been caused by exposure to excessive heat
  • Damage to storage tanks, vents, and overflow pipes
  • Debris, such as ash and sediment entering uncovered wells or storage tanks.

Exposed electrical wiring to the well poses a significant electrical safety hazard with potential for an electrical short to the metal casing. If the electrical wiring has been damaged by fire, do not handle the wiring or touch the casing.

If your well has been damaged by fire, contact a local licensed and bonded well constructor or pump installer to determine the extent of the damages and what must be done to either repair or decommission the well. If you think a fire may have damaged your water supply, bring bottled water back with you when you return to your home.

Water Taste and Odors

You may notice that your water tastes or smells earthy, smoky, or burnt.

  • If so, you may need to thoroughly flush your water lines

Inside Your Home

To the extent you can, visually check the water-supply system, including plumbing, for any damage, signs of leaks, or changes in operation. You should check to see if your well and plumbing system maintained positive pressure during the fire. This can be done by simply turning on a faucet in the household to see if water flows.

  • You should not hear any air being released from the faucet.
  • The flow of water should be steady and uninterrupted.
  • If you do hear air escaping from the faucet with water intermittently spurting out when it is turned on, that is an indication that your well and household plumbing had a loss of pressure and may have been damaged.

If You’ve Had Loss of Water Pressure

If your visual inspection shows that there was a loss of pressure or the water system has been damaged, it is likely that your water may be contaminated with bacteria.

  • Damaged components should be repaired or replaced.
  • Anytime a water system loses pressure, the water should be tested for the presence of bacteria before it is used for drinking or cooking.
  • Anytime the well or water system is repaired, it should be disinfected after a repair is made and then tested to ensure the water is safe for drinking or cooking.

Testing Your Well for Bacteria

When testing drinking water for the presence of bacteria, it is necessary to collect a sample and deliver it to a CA-certified laboratory.  Bacteria samples must be collected in an approved container provided by the laboratory. When collecting a sample, follow the instructions that come with the bottle and return the sample bottle to the laboratory in the recommended time.

Using your Water while you wait for Test Results

You can use your water for showering and flushing toilets. Take care to avoid swallowing water from showers or baths. You should not use your water for drinking or cooking purposes unless you have boiled or disinfected it. This caution includes not washing dishes or other cooking utensils in it. While you are waiting to receive the results of bacteria testing, you can boil the water you will be using for drinking and cooking for at least 1 minute at a full rolling boil.

Well Disinfection

You can also disinfect your well and water system while waiting for sample results. If the well tests positive for the presence of coliform bacteria, you should have the well and water system disinfected. Instructions for disinfecting wells can be found below. Additional information may be found on our Well Water Quality page. Wells must be maintained to prevent health hazards. Take steps to ensure your water is safe to drink after an emergency.

Disinfection of Private Domestic Water Wells

  • Disinfection of a well is recommended to eliminate disease causing organisms. A well should be disinfected following a repair, maintenance or replacement of the pump or if the power has been off for an appreciable period of time possibly causing the pressure tank to loose pressure and the distribution system to back siphon into the well causing possible contamination.
  • Use only a freshly opened bottle of liquid chlorine, as the solution weakens with exposure to air.
  • It is advisable to premix the liquid chlorine into a 5-gallon container prior to pouring the disinfectant into the well. The recommended dosage for a 50.0 PPM chlorine residual is 2-3 cups of 8.25% liquid chlorine for a standard well.
  • Mix thoroughly after adding the chlorine solution. If the well is deep, turn the pump on and off to surge the well.
  • Allow the system to rest overnight for 24 hours.
  • To reduce excess chlorine, pump the well several times then turn on all the outside faucets until the chlorine odor is at an acceptable level.
  • Take a bacteriological sample into a certified private laboratory for analysis. If the test results for total coliform indicate unsafe conditions, then repeat disinfection procedure.

Damage to Wells and Septic Systems

Wells and onsite wastewater (septic) systems have most of their functional components below ground and are typically more resistant to fire damage. However, it is important to inspect your well and septic system for damage to PVC piping above or near the ground that may have been impacted by heat. If your well or septic system has been damaged, or is malfunctioning, discontinue use and refer to the following literature on how to evaluate your well and septic system:

Contact Environmental Health

If you have any questions regarding this document or your health and safety with regards to returning to your home, please contact Environmental Health at (707) 565-6565.