top of page


In San Juan County, where pristine landscapes and rural living are cherished, the reliance on potable well water is quite common. However, this seemingly pure source of water can harbor various elements that pose health risks. Understanding the potential contaminants and their effects is crucial for residents as well as implementing a regular testing schedule and effective filtration system, if needed, becomes paramount in ensuring water safety.

Types of water sources in the islands include:


  • Individual Private wells


  • Shared well; 2 households. These systems should have a recorded shared well agreement with easements for maintenance and access.  Depending on the volume, individual holding tanks may be required.


  • Group B water system; 3-14 households but less than 25 total users.  In the late 1990s, the County began managing the approval process for this group of water systems.  The County requires that the system have a maintenance agreement, access easements, a protection zone and regular testing with an assigned purveyor.  The County requests the purveyor to submit bacteria and nitrate tests annually to remain in “good standing”.  


  • Group A water system; 15 plus households.  These systems are larger providers such as Roche Harbor Water or the Town of Friday Harbor.  The system’s testing reports are reviewed by the State and must comply with the State’s requirements for maintenance, testing and notifications. 


As stated above, Group A and B water systems are on a regular testing program.  For individual or 2 party shared wells, it is up to the property owners to create a regular quality testing schedule.  Most owners of individual or 2 party shared wells should be on an annual schedule.  


As part of a purchase contract, agents recommend that the buyer have the well tested for quality and quantity prior to the feasibility study expiration.  


We typically recommend that a buyer have the proposed purchase property well tested for Bacteria and a San Juan Short.   The fee is around $400, and the process takes about 15-20 days.  The service provider will deliver the water sample to the mainland to Edge Analytical for the laboratory work.  The San Juan Short report tests for arsenic, barium, fluorides, sodium, electric conductivity, chloride and nitrates.  The County also requires these same two tests plus quantity testing prior to issuance of any new construction building permits.  


At a minimum, these two tests should be ordered by property owners on private or 2 party shared wells annually.  It is possible to purchase a sample testing kit and take your own sample and deliver it to Edge Analytical but there are some risks. You must ensure that the water sample is taken at the best location in the system and that the sample is submitted to the lab prior to the sample expiration.  Some things are best left to the professionals.  Agents involved in a transaction should not take the water tests due to the amount of liability.


Edge Analytical has numerous other report options that test for more elements that should be considered.  Recently, during a purchase transaction, we noted high levels of manganese in a well and the service provider reported, although not common, high levels can be present in our wells in the County.  Due to this experience, I now discuss more thoroughly with my buyers their options and encourage them to order the more extensive testing report as it is just a few hundred dollars more.  I order the report with the extensive testing for my personal well on an annual basis.


After the report of Per- and Polyfluoroalkyl Substances, or PFAS in one of the Group A Public Water Systems on San Juan, the other community water systems on island immediately had their systems tested for PFOA and PFOS.  Thankfully, no other systems tested positive for those contaminants.  Now all of the Group A and B public water systems must start testing annually for these contaminants.  


The report from the lab will indicate whether each element tested passed, exceeded or failed the Maximum Contaminant Level (MLC).  This is the maximum permissible level of contaminant in the water as established by the EPA.  


Generally, the contaminants and their impacts are listed below:   

Bacteria and Pathogens: Bacteria in the well indicate possible contamination.  If the water contains harmful bacteria like E. coli or pathogens, it can cause waterborne diseases, impacting both physical health and well-being of the user.  Bacteria removal can be addressed with a filter system or a one-time shock chlorination treatment.   The most common treatment is a dose of bleach into the system followed by a purge of the treated water.  

If the bacteria reoccur, then an Ultraviolet Light Purifying Filter System should be installed.  If the well has other similar type contaminants in addition to bacteria, then a Reverse Osmosis System should be installed to provide an added layer of protection.   

Heavy Metals: Elements like arsenic, fluorides, barium, lead, manganese and mercury can seep into well water, posing long-term health risks such as developmental issues in children and organ damage.  A Reverse Osmosis System is used for eliminating heavy metals, bacteria and pathogens, ensuring comprehensive water purification.

Nitrate Contamination: Agricultural runoff or septic systems can introduce nitrates into well water, leading to methemoglobinemia or "blue baby syndrome," especially concerning for infants.   An ion exchange system at your main water line can address nitrate or sulfate levels.

Pesticides and Herbicides: Agricultural areas are susceptible to groundwater contamination, affecting well water with harmful chemicals that may have adverse health effects.  Activated Carbon Filters effectively remove organic contaminants, such as pesticides, and improve taste and odor.

High Chloride levels or Saltwater Intrusion.  This event typically occurs on the waterfront properties.  When it occurs, it is very difficult to address on individual wells or 2 party shared wells.  The larger water systems such as Group A and B, have typically addressed the problem with a desalination plant.  These plants are extremely costly, and obtaining permits can be very time-consuming.  We have numerous desalination plants in the County that work well for the various subdivisions, the cost to install and maintain is shared amongst the entire neighborhood and therefore more affordable.   A typical hook up fee to a desalination plant is around $45,000 plus trenching/meter.

When the saltwater intrusion is on an individual or 2 party well, the correction process starts with raising the pump in the well above sea level with the thought that the salt water will remain in the bottom of the well casing as salt water is heavier.  In conjunction with this effort, a flow restrictor is installed on the system.  This device only allows the water to flow at a minimum amount which removes pressure off the well. 

Legally, a whole house Reverse Osmosis System is not allowed on individual use wells for the purpose of addressing saltwater intrusion.   The State requires that the well be decommissioned, if the Chloride level is above 250 mg/l. This is to protect the entire aquifer from a source of intrusion.  However, Reverse Osmosis systems are allowed to be installed on individual use wells for other contaminants.  

Other Options to address Saltwater Intrusion:

Subject to the amount of land, drilling another well on the subject property is an option.  The wait list for well drilling is currently 24 months.  The cost to just drill a well is around $10,000 for 300 feet in depth.   

Water catchment is a viable alternative water source; however, the system must be designed by one of the County’s approved licensed designers.  Normally the roof of the structure is used for collection so it must be an acceptable material type plus there must be room on the property for the required storage tanks.  The County recognizes water catchment as a water source for the permitting process; however, conforming lenders are very cranking about this type of system and a portfolio lender may be the only option, if financing is required.  Conforming lenders sell their loans into the secondary market to investors such as FNMA or FHLMC so the loan must meet their guidelines.  Portfolio lenders retain the loans on their books.

Water hauling with a storage tank is another option as a water source, and the County does recognize it as a stand-alone system; but again, any lender involved may have to be a portfolio lender.  

Health effects of contaminants in your drinking water include:

  • Gastrointestinal Issues: Contaminated water can cause stomach cramps, diarrhea, and nausea.

  • Developmental Concerns: Children exposed to certain contaminants may face developmental delays and cognitive issues.

  • Cancer Risk: Prolonged exposure to carcinogenic substances increases the risk of cancer, emphasizing the need for proactive measures.

There are numerous brands of filtration systems, and your service provider will recommend the one best suited for your drinking water system.  The pricing and type of contamination will help you decide if you want the filtration to be a whole house system or a point of use.  The service provider will also give you a quote for the cost to purchase and install the filter system.  In my experience, the point of use filtration systems range from $3000 to $15,000.  The whole house systems are $5,000-$50,000

Of course, the point of use system is more affordable, but they do not have the longevity, so you might be buying replacements parts on a regular basis.  These types of systems produce about 100 gallons or less per day.  If you have children in the household, a point of use filter should be installed on every faucet.  Kids often forget if the filter is only installed in the kitchen for drinking water. 

The whole house systems are superior but costly and are on the high-end of the pricing range quoted above.  These types of systems typically have a warranty and are able to produce adequate water to run the entire household.   

It is important to note that if you are on a Desalination Water System or Reverse Osmosis System, as your primary residence, you need to take vitamins and supplements as both of these systems have filters that strip out the important elements that you need to keep good health.

If not corrected, well contamination issues may cause the property to be less desirable. Most buyers have little interest in purchasing a home or property where there is no drinking water source.

Residents on our islands must be vigilant about their well water quality. Regular testing, coupled with the appropriate filtration system, ensures a safe and reliable water source.

Bottom line:  Test your wells annually.    Living Water Systems is an excellent service provider for testing.  They can be reached at 360-378-0975.  Al and Fritze Mauldin.  

Another very important note is to be aware of your water system’s function or lack thereof.   If your pressure tank is not holding pressure or running more than usual, then your well maybe filling your holding tank(s) more often.  This may be a sign of a leak in your water line, holding tank or perhaps a faulty pressure tank, faucet or a running toilet. Not only does this place a hardship on your well to perform, if you run it dry, you may risk saltwater intrusion.  Further, you could saturate your drain field if the leak is draining into the septic system. All these items are costly issues to repair.  You should monitor your system regularly and take notice of any function issues, then make the repair in a timely manner.  Unfortunately, I speak from experience, says the gal with the backhoe digging up her driveway.       


As with all my articles, the opinions expressed herein are solely my own.  And these opinions are based on my personal experience, observations, and from interviewing and reviewing both public and non-public information sources.  Anyone interested in understanding their well test results should seek out further information from official sources.   Our County Health Department can be reached at 360-378-4474.

Written by:


Merri Ann Simonson

Coldwell Banker San Juan Islands Inc.



bottom of page