In the UK, a common query is “Can I Run Rainwater Into the Sewer?” This is an important subject to bring up because any drainage-related project you are working on must adhere to local and federal regulations.
What is Surface Water?
Any water that is present on top of the Earth’s surface is referred to as surface water. It can also be used to refer to rainwater that has already reached the ground. Normally, this phrase refers to rivers, ponds, lakes, and streams in addition to other sources. Surface water should never be combined with wastewater, and as a result, should never be discharged from a building into a wastewater sewer.
What Happens When Rainwater Enters a Foul Sewer?
When a home permits rainfall to enter the public sewer, especially during a storm’s tremendous surge, it is allowing the water to obstruct the first tank of the public treatment works’ treatment process. All of the separations that have already occurred in the primary settlement chambers is canceled out by this.
All the fats, oils, and other materials that would have been filtered out can then proceed through the system and be discharged into rivers and other watercourses. As a result, the water becomes contaminated. For this reason, you should make sure that your rainfall drains away to the proper area rather than the public sewer system.
Some regional authorities (your neighborhood water companies, who are in charge of maintaining the public sewers in your area) may even impose fees on you for the expense of surface water entering the sewage system.
We want to help homeowners become aware of how much water goes through each of their particular drainage systems each day so they can prevent a bigger issue. As an illustration, on a day with favorable weather, a typical three-bed house will typically release roughly 1m³ of water in 24 hours. The sum can increase to more than 25m3 per day when surface water that is improperly draining from your patio and rainfall pipes are added.
When you consider that this problem affects at least half of the households that discharge there, just think of how much water may be overflowing the public sewer system and producing more and more pollution!
Are there any issues that you should be worried about if rainfall gets into a foul sewer system?
The first stage of the treatment process is immediately disrupted when rainfall from a residence drains into the same area as a public sewer. This means that once the separation process has begun, combining the two types of water cancels it out, defeating the purpose of bringing contaminated water to a treatment facility.
When rainwater and bad water meet, the bad stuff in the bad water, such as oils and undesirable fats, can no longer be filtered out and will actually travel through the system. This will ultimately run or discharge into a river or some natural water source. The main reason you should look for another spot for your rainfall to run into is that this can cause pollution. In the worst situation, your neighborhood water company might get in touch with you. If it turns out that you are inadvertently pouring rainfall down drains into a dirty water system, you might be hit with a big fine!
The majority of people are unaware of how much water actually travels daily via their own drainage system, yet this is an important fact that should not be ignored. This is due to the fact that you can avoid any future worse issues if you are aware of roughly how much water is leaving your property.
Looking at a typical three-bedroom house serves as a good illustration for the majority of individuals. In this scenario, assuming regular weather, the typical discharge for a family of this size over the course of 24 hours is 1 m cubed. However, if there is water in places like your yard that is not draining properly, this water combined with the rains can result in volumes as high as 20 m cubed and more.
This puts into perspective why you must divert your water to the proper location and prevent it from flowing into the public sewer, mostly because there is a good probability that they will get overloaded, which over time results in significant pollution, floods, or overspill.
Check out another one of our blog entries here where we go into detail about all of this if your property has a combined underground drainage system!
What if a Property Has Combined Drainage?
Surface water entering the public sewer is often only accepted by water utilities if there are no other options. Your local government should only deviate from this rule if you have a combined sewer system (usually found in properties that are Victorian, or built before 1970). This means that if your drains remove both surface water and sewage, they will typically be permitted to remain in that state.
However, you will probably be required to make sure that the flow is kept separate until it leaves the property line, in order for it to enter a single length of combined sewer from a single manhole. In the event that separate foul and surface water drainage systems replace the sewers in the future, this assures that the flows will remain distinct.
In any other circumstance, you must make sure there are two distinct pipes, one for the surface water drains and the other for the filthy water drains.
Applying for Combined Drainage
A soakaway is the most popular choice for surface water drainage in a home. Your neighborhood water provider will need the following proof if you can’t connect to a soakaway for whatever reason:
Where should you direct rainwater that has accumulated in drainage pipes?
A Drywell Or A Ditch
A frequent choice for rainfall drainage is a ditch or drywell, which is essentially a hole constructed in the earth that A frequent choice for rainfall drainage is a ditch or drywell, which is essentially a hole constructed in the earth that The purpose of the ditch is to provide a dry area for the water to flow through so that it has time to soak up and drain into the surrounding soil, preventing floods.
A non-woven geotextile membrane can be used to cover the ditch or drywell, minimizing the accumulation of undesired debris while yet allowing the water to drain away. Additionally, gravel of some kind should be used to fill the ditch because it serves as a fantastic absorption layer.
A Headwall Charge
Sometimes it is not a good idea to dig a deep ditch or trench in your garden. In this situation, channeling water into an existing water flow can be an option, provided you have permission to do so and this does not violate any of your area’s bylaws.
To make this alteration, you would need to direct a sturdy pipe—typically twin wall drain pipes—in the direction of the water source and enclose the outlet section with concrete to protect the bank from any damage from stormwater. Be sure to get in touch with them before deciding that this approach will best meet your needs because your local authorities will have a specification that you must adhere to in order to comply with their rules before putting a headwall charge.
A Soakaway Mechanism
The best way to understand a soakaway system is to picture it as an underground reservoir that is set up to collect rainwater from frequent showers in order to lessen the likelihood of floods. Installed underground, the soakaway crates (also known as attenuation crates or cells) are covered with a non-woven geotextile membrane to prevent mud and dirt from getting within the system and interfering with how well it should work.
While no debris or dirt can enter the drainage system due to the use of non-woven geotextile fabric, water can still enter the soakaway system where it will be gently released back into the earth through a process known as infiltration. Check out our soakaway crate kits, which include all the parts required for a whole system.
Rainwater and Private Systems
The ability to dump rainwater or roof water into drains that connect to private systems like septic tanks or sewage treatment facilities is frequently questioned by homeowners. This question typically asks whether the home has the legal authority to mix sewage directly or indirectly with surface water or roof water.
Can I Pour Rainwater Down the Sewer?
In any scenario, our professional insight and counsel will confirm that rainwater and roof water cannot be disposed of into private systems’ drains. This is because, in accordance with the General Binding Rules, the homeowner is also legally the system’s operator and bears full duty for ensuring that rain and surface water drains into the sewer system intended for uncontaminated water.
When surface water enters your private system, all separation is destroyed, and sediments, fats, and oils are permitted to pass through the tank in the same way they would if they had entered the public sewage. The main distinction is that, if not released to (and polluting) a waterway, these could end up congealing in your drain field. When this occurs, the pipes will gradually stop flowing and get waterproof, causing the system to malfunction.
Are there any more elements that I should think about when it comes to rainwater?
Sending your unwanted raindrops in their direction would not be the ideal choice because it is always best to have good relations with your neighbors. This is because if they don’t take the required drainage procedures, it could result in damage to their property that you might have to pay to repair.
If connecting to a foul drain system would be a better choice, you must make sure that you have discussed this with your local authorities because you must have their complete consent to do so.
Wildlife is the final consideration that you must take into account. If your runoff or rainwater drains or runs into a wooded area, it is ultimately terrible practice.
The main deterrent to doing this is the potential impact on tree root development rates, which could eventually obstruct pipelines. You should be aware that it might harm animal habitats as well.
Feel free to call our staff with any questions regarding the blog post if there is anything you are unclear of. We would be pleased to respond to your inquiries as best we can.