Orange, slimy sludge in your sump pit or at the end of your drain? It is probably iron ochre. Here is what it is, why it clogs drains and how to manage it.
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Published October 12, 2026 · 6 min read · By the Fissure et Drain XT team, RBQ licence 5863-7364-01
Definition
What is iron ochre?
Iron ochre is an orange, rust or brownish deposit, often gel-like, that forms in foundation drains. It appears when groundwater contains dissolved iron. When it meets air in the drain, natural bacteria turn the iron into a slimy material that sticks to the pipe walls and the surrounding stone.
Over time, the deposit narrows the pipe, then clogs the drain’s perforations. Water can no longer drain away and builds up against the foundation.
Where
Why it is common on the North Shore
Iron ochre depends on the soil and the groundwater. Several areas of Laval, Terrebonne, Blainville, Mascouche and Lanaudière are prone to it. Two neighbouring houses can be affected differently, depending on the drain’s depth and the water that feeds it.
A drain affected by ochre can clog in just a few years, while a healthy drain normally lasts decades.
Signs
How to recognize iron ochre
→Orange or rust-coloured sludge in the sump pit or at the drain outlet
→Orange stains on the basement floor, at the joint between the wall and the slab
→A sump pump that jams or wears out early
→An iron or rotten-egg smell near the sump pit
→Water in the basement after rain, with no obvious crack in the foundation
Confirm
Why a camera inspection is the only real proof
Sludge in the sump pit shows that ochre is present, but not how far it has clogged the drain. A camera inspection shows the inside of the drain along its full length: light deposits, a narrowed pipe, clogged perforations or a pipe that has already collapsed.
The camera goes in through a cleanout. If there isn’t one, we dig down to the drain to install it. It is then used for every future inspection and maintenance, with no digging.
The camera screen shows the inside of the drain: deposits, a narrowed pipe or a crushed section.
Solutions
Solutions that last
Drain cleaning
If the camera shows the drain is in good shape, we clean it with high-pressure water to remove the deposits. With ochre, maintenance has to be repeated regularly: the deposit comes back.
Cleanouts
Permanent access points to the drain let you inspect and clean it without excavating. They are the key to living with ochre in the long run.
Drain replacement
If the drain is deeply clogged, crushed or made of clay, it has to be replaced. In an ochre-prone area, maintenance access is planned from the start.
Regular follow-up
A periodic camera inspection lets you clean before the drain clogs, instead of finding out with water in the basement.
A replaced drain in clean stone, with the membrane on the foundation.
Frequently asked questions
Iron ochre
Is iron ochre dangerous to your health?
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It is not recognized as a health hazard. The real danger is to the house: it clogs the drain and can lead to water leaks and dampness in the basement.
Can iron ochre be eliminated for good?
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Rarely, because it comes from the groundwater. It is managed instead: a drain reachable through cleanouts, plus regular inspections and cleaning.
How often should a drain with ochre be cleaned?
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It depends on how much ochre there is. Some drains need maintenance every year, others every few years. A camera inspection sets the right schedule for your house.
Is iron ochre covered by insurance?
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Drain maintenance and replacement are generally not covered. Water damage depends on your policy and its endorsements. Check with your insurer.
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The warranty covers only workmanship defects and construction flaws related to the work performed by Fissure et Drain XT. It does not cover damage caused by ground movement, soil defects, earthquakes, exceptional flooding, work done by third parties or any unauthorized modification after the work is completed. Warranty transferable to the new owner upon written notice. RBQ 5863-7364-01.
