Your septic tank lid might not seem significant, but it's one of the most critical parts in the system. A weak or broken lid will cause odors to escape and foreign objects to enter into the tank which can cause blockages in the system. It is important to replace this lid on a regular basis. Several septic tank installations have special risers that position the tank lid at ground level. If yours is not fitted with a riser, you will need to dig for the lid of your septic tank. Typically, all components of the septic tank, including the lid, are buried between 10cm and 1 meter deep. Over time septic tank lids may suffer wear and tear, requiring a replacement. Removing a septic tank lid is relatively easy and is normally done for emptying and inspecting the system.

Eventually, your septic tank will fill with solid sludge, and it will need to be emptied out to preserve healthy working conditions. Depending on the size of a septic tank, a good rule of thumb is to have it pumped out every three to five years by a legitimate wastewater carrier (you must legally keep a record of your waste transfer note). It is essential not to let your septic tank get too full as untreated sewage may start to overflow into the environment or back up into your house.

Follow this basic, step-by-step guide, on how to remove and replace a septic tank lid.

1. Find your Septic Tank Lid

The first step to removing or replacing a septic tank lid is, of course, to find it. This can be more difficult than it sounds, especially if you are not the first owner or have no experience with septic tanks in previous households.

Just ask

We would recommend asking appropriate people as the first step to finding your septic tank lid; either contact the past property owners or your local septic emptying firm that may have emptied the system in the past. They may be able to help you locate the position of your septic tank and save you a lot of time and effort looking for it. A diagram of your septic system is usually included as part of the property inspection during the purchase process, this should be made available for you if needed.

Use a Metal Detector

A second option to locate a buried septic tank is to use a metal detector. With the use of a metal detector, you can be led to the approximate location to start a more targeted search. When you reach an approximate area, you can use a metal pole to poke into the earth and locate the tank more precisely. This can be time-consuming if the deed to your property was not written accurately.

Follow your Pipework

A third option is to follow the pipework that comes from your house. In general, septic tanks are required to be at least 7 meters away from a property, although your septic tank could be anywhere between 7 and 25 meters away. Finding your outlet pipework may give you a better indication of the positioning of the septic tank in relation to your property. Note that the tank is likely to be below the property if the system is gravity fed. Observe any patches of grass or vegetation that looks greener, longer and healthier than the rest in the direction of the pipework. You may then use a metal detector to confirm the exact position of the tank before you begin digging.

2. Dig out your Septic Tank Lid

Once you have found your septic tank, simply use a shovel to excavate the ground around the tank until you locate the lid. Most septic tanks come with a standard lockable access cover and frame that can be opened with a key to enable access for emptying/servicing. Dig up the ground to create at least 40cm of clearance around the lid.

Often, the septic tank lid is above ground and digging will not be necessary. In this case, you will simply need to clear the longer grass in order to access the lid.

3. Determine the Type of Replacement Lid that You Need

Measure

It is important to accurately measure the width of the lid that you have and to identify the material of the lid. It could either be PVC, a high-density polyethylene, or concrete. If the lid to your septic tank is concrete, you may want to consider replacing it with a PVC or polyethylene version as the latter are more waterproof and lightweight. It is unusual to find a direct replacement for old septic tank lid but we would suggest contacting your local builders merchant to see if they have a similar size in stock or if they are able to fabricate a lid to suit. Depending on the size of the system your tank could have two or three lids.

If you have an old style Klargester diamond shaped septic tank lid, this has unfortunately been discontinued by the manufacturer. Klargester now recommend this lid is replaced with a 600x600mm composite sealed manhole cover and frame. A diagram to replace your Klargester diamond shaped lid can be found here.

If your septic tank is beneath an area where vehicles or heavy machinery may drive or operate over it, special heavy-duty septic tank lids are necessary.

4. Remove the Septic Tank Lid

Some septic tank lids have handles to pull, but most will require a pry bar to lift them out of their seating. Set the pry bar in the seam and press down. As the lid lifts out of its hole, move it to the side. Please have assistance for this step.

If your current septic tank lid is made of concrete, you may require an excavator to lift and remove the lid and risers. In this case, hiring a contractor may be more ideal as they will have the equipment and the expertise to install the new lid if you prefer to stay with a concrete lid.

If what you have is made with PVC or polyethylene, you should be able to remove the septic tank lid independently — or with some assistance (as recommended by manufacture’s instructions). Make sure to follow the manufacturer’s instructions with any septic tank lid replacement.

You will need to exercise extreme caution if the septic tank lid has sunken treat the area as highly hazardous. An unsafe septic tank cover poses a danger of collapsing and could result in someone falling into the tank – which can be fatal. Keep area safe until you’ve had the tank inspected and opened for further inspection by a professional service provider.

At all times, be absolutely certain that your septic tank lid and clean-out access covers are secure and durable so that it will be impossible for anyone to fall into the tank and that a child could not remove the cover.

We would advise making a diagram indicating the location of your septic tank for future reference.

Septic Tank compliance check

If you are responsible for a property with a septic tank, you need to be aware of the new regulations concerning your legal obligations. While you are checking on your septic tank, you may want to do a quick compliance check to ensure the system meets current 2020 general binding rules for septic tanks. In 2015 the Environment Agency brought out new legislation outlining that by 2020 any property with a septic tank which outfalls to a river, stream, ditch, pond etc. would need modifying to meet new standards.

If your current sewage treatment system has EN12566-3 certification, this means it is legal and safe to discharge into a watercourse and no action should be required. Septic tanks that currently discharge via a drainage field into the ground are not usually expected to be upgraded.

It is your responsibility, as the owner of the septic tank or sewage treatment system, to ensure you comply with these rules. If you are unsure whether or not your sewage effluent is discharged to surface water or would like further information RA Dalton Waste Water Specialists offers a septic tank compliance report and is happy to give advice and support throughout the process. Call their friendly office team on 01388 537030.

Upgrading your septic tank to become compliant with new rules

There are three main ways in which you can comply with the new regulations – each option will have site specific conditions to consider:

1.       Swap your septic tank for a sewage treatment plant

Sewage treatment plants produce a cleaner form of water, suitable to discharge straight to a watercourse.

2.       Install a drainage field

This will take the waste water from your septic tank, and disperse it safely into the ground without causing pollution.

3.       Connect your existing tank to mains sewer

Your local water company will be able to advise whether or not connection to mains sewer is a feasible solution, however this is a less likely option.

The new legislation aims to have a positive effect on our environment. Your septic tank must meet the new, higher standards. This includes being the correct size, installed correctly, regularly emptied and maintained. These standards are available to find at https://www.gov.uk/guidance/general-binding-rules-small-sewage-discharge-to-the-ground.