Smelly sulfur water…what to do…?!

One of the most common well water quality complaints on the West Coast is dealing with smelly, rotten-egg water or sulphur water.


The telltale rotten-egg smell is almost always caused by H2S (hydrogen sulphide) — a gas produced naturally and as a byproduct of bacteria (that is not a pathogenic strain) that “eats” sulfur.


Sometimes a homeowner may find it is worse in the late spring or late fall as ground water levels are falling/rising through strata that carries more sulphurous bearing rock. In other areas it is overwhelming and terrible year-round.


On Gabriola, there are degrees of intervention we employ based on how bad it is:


  1. A) Intermittent , or with the seasons:
  • Use a good quality activated coconut carbon filter — either carbon block or granular GAC; and plan on changing out every 4-8 weeks (for a normal-sized filter) or every 3 -6 months for a Big Blue 10″ filter.
  • If present more on the hot water than cold, the anode in the hot water tank is most likely contributing to the creation of H2S. Either swap out with an aluminum anode or cut off the old anode rod and put plug back in. 

IMPORTANT NOTE: this is commonly done by many people and plumbers in rural areas with H2S issues, but it voids your h/w tank warranty if it fails prematurely to its rated-life (rare). This is up to you!

  • Occasionally (once or twice per year) dose your h/w tank with plain ordinary household bleach (5-6% chlorine) by putting 1-3 cups in your filter housing and turning on a h/w tap for several minutes to draw the bleach into the h/w tank. Let it sit for 12 -24 hours then purge tank via drain valve or use up bleachy water in a load or two of hot-water laundry (e..g. rags and whites). Very effective if done after you have the anode removed.
  • Vent or have lots of fresh air in your bathroom when showering/bathing.
  1. B) Chronic and powerful on hot and cold water lines:
  • Install an automatic backwashing Manganese Greensand filter — but only if you have the well capacity (pump rates exceeding 5-7 gallons per minute) and reliable quantity to operate the filter system. A few tests and calculations are needed, as well as qualified installation.
  • Install a 1200 to 2400 gallon cistern and pump from well to cistern, so that water sprays in and aerates and offgases, then re-pressurize and pump to house service. The cistern should have a screened, critter and insect proof 4-6″ bulkhead opening so that there is plenty of venting and air flow for off-gassing. Sediment and carbon filters should come afterwards.
  • Install an automatic backwashing activated carbon filter — but it will need re-bedding with new carbon every 4-6 years. Results can be mixed.

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