Septic tank and treatment plant maintenance on the Isle of Man
A septic tank or treatment plant that's looked after can work well for many years. One that isn't is more likely to fail, and can damage its drainage field. Here's what it needs, and how we can help.
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- Septic tank and treatment plant checks
- Planned drain maintenance
- Advice on when emptying is due
In short
- Emptying
- On the Island, septic tank emptying is carried out by Manx Utilities, on request. As a general guide, Manx Utilities says every 3 to 5 years, depending on the tank's size and how many people use it.
- Maintenance
- We check and look after septic tanks, treatment plants and drainage fields, and put right what we find.
- Planned drain care
- Regular jetting and camera checks for properties with repeat problems, such as rental homes, food businesses and houses with trees near the drains.
- Why bother
- Most failures start small. Catching them early usually means a simple fix rather than a new drainage field.
- What it costs
- Your first consultation is free, and we give you a free estimate before any work starts.
How often should a septic tank be emptied?
There isn't one answer for every tank. Manx Utilities' general guidance is every 3 to 5 years rather than every year, depending on the size of the tank, how many people live in the house and how much water you use. Manx Utilities also points out that emptying too often can upset the bacteria the tank relies on.
A simple check you can do yourself: look at the water leaving the tank's outlet. Light grey water is normal. If you can see dark solids coming through, the tank needs emptying (known as desludging).
Signs it's overdue include slow drains throughout the house, smells, and wet ground over the drainage field. It's worth acting on: solids carried into a drainage field are a common reason fields fail.
Booking an emptying
Manx Utilities says its tanker usually visits within a few weeks of a request, so book before it becomes urgent.
Septic tank emptying is booked with Manx Utilities, which runs the tanker service on the Island. You can request it through their website.
We can tell you whether your tank actually needs emptying, check it over afterwards, and deal with anything that turns up, such as a blocked outlet, broken dip pipe or struggling drainage field.
What we check
Septic tanks
- Sludge and scum levels, and when emptying will be due
- Inlet and outlet pipes, dip pipes and the dividing wall
- Covers, access and ventilation
- That no rainwater is getting into the tank
- The drainage field: wet ground, smells or signs of overloading
Treatment plants
- The blower and its filter, and the alarm
- That air is reaching the chamber where it's bubbled through, and the process is working
- Sludge levels, and when emptying will be due
- The outlet, and how clear the treated water looks
- Wear parts, serviced as the manufacturer recommends
Preventing problems instead of reacting to them
Some properties are prone to blockages: restaurants and cafes with fat going down the sinks, rental homes where you can't control what gets flushed, and houses with trees close to old clay drains. For these, a planned visit every so often is usually less hassle, and less expense, than an emergency call-out.
- High-pressure jetting to clear fat, scale and silt before it builds up
- Root cutting where roots are getting in
- Camera checks, so you can see the drains' condition over time
- A written record for landlords, agents and insurers
We'll suggest how often is sensible for your property, and we won't push visits you don't need.
Looking after your system
Do
- Flush only human waste and toilet paper
- Use bleach and cleaning products sparingly
- Spread out heavy water use, such as several loads of washing
- Keep a note of when the tank was emptied and serviced
- Keep the covers and the drainage field clear and accessible
Don't
- Put wipes, sanitary products, fat, oil or grease down the drains
- Connect rainwater pipes to the tank
- Park, build a shed or lay paving over the tank or drainage field
- Ever climb into a septic tank: the gases in it are dangerous
If your system was installed under the current Building Regulations, there should be a notice in the building explaining the maintenance it needs.
Emptying and maintenance FAQs
Who empties septic tanks on the Isle of Man?
Manx Utilities runs the septic tank emptying service on the Island, and you can request it through their website. We can check the tank before and after, and fix any problems the emptying shows up.
Does a treatment plant need emptying as well as servicing?
Yes. Servicing keeps the blower and the treatment process working, and the sludge that collects in the tank still has to be removed from time to time.
My treatment plant alarm is on. What should I do?
Check that the power is on and the blower is running. If it isn't, or the alarm stays on, call us. Without air, a treatment plant stops cleaning the water properly.
Are septic tank additives worth buying?
A tank that's used normally already has the bacteria it needs. Additives aren't a substitute for emptying it when it's due, and they won't rescue a failed drainage field.
How often should drains be jetted?
Most homes never need planned jetting. For food businesses, rental properties and drains with a history of problems, we'll suggest a sensible interval based on what the camera shows.
Related pages
Not sure when your tank was last looked at?
Tell us what system you have and what you've noticed, and we'll suggest what it needs.