Sewage Spills

Sewage bacteria

We take a look into what sewage is as well as its dangers and how to detect, prevent and solve sewage spills.

What is sewage?

Sewage is wastewater, which is disposed of by the flushing of toilets and the use of sinks, baths and showers, which is then taken underground into sewers to be treated.

In domestic properties there are 3 types of wastewater, black, grey and yellow:

  • Blackwater is wastewater that comes from toilets, sinks, drains and dishwashers, containing multiple contaminants like faeces, toilet paper, toilet wipes, food and cleaning up liquids. Due to this contaminant, this wastewater is the most hazardous and full of viruses.
  • Greywater comes from the same locations as blackwater but doesn’t include contaminants. It comes from sinks, baths, showers, and washing machines.
  • Lastly, yellow water is pure urine with no other contaminants included.

Businesses also take part in producing wastewater, known as ‘trade effluent’, meaning liquid waste being discharged into sewers through an industrial process on trade premises’.

Dangers of a sewage spill

Raw sewage spills and overflows contain a variety of harmful microorganisms, including bacteria, fungi, parasites and viruses.

Exposure to these viruses can also occur through the toxic, flammable and asphyxiating gases, putting homes and businesses at risk.

When exposed to the public, whether this be in commercial or domestic properties, it can lead to acute illnesses such as diarrhoea as well as more severe illnesses (listed below), and in the worst-case scenario, death.

  • Cryptosporidium and Giardia
  • Gram Negative Bacteria
  • Hepatitis A
  • Leptospirosis
  • Gastroenteritis
  • Tetanus

Not only can a sewage spill be harmful to us, but it can also be harmful to the environment and our water supplies.

Cause and prevention of sewage spills

The BBC recently reported that in England, water companies discharged raw and untreated sewage into rivers over 400,000 times more in 2020 than in 2019, according to figures published by the Environment Agency. Part of this reason was due to wet wipes being let in the waterways, accounting for 90% of sewers to block.

Sewage spills can be caused by plumbing that is damaged and may have deteriorated over periods of time. These can spill slowly or rapidly, therefore, ensuring that the matter is dealt with quickly will help minimise the potential of exposure to viruses.

Other reasons for sewage spills can be due to blockages, such as:

  • Pouring fat down the sink (these harden and build up in pipes)
  • Flushing wet wipes and paper towels (these take years to break down)
  • Dental floss (these don’t break down naturally)
  • Coffee grounds (spread these in the garden instead to help plants grow)
  • Nappies (these expand in water)
  • Sanitary products

By taking the above into consideration and sticking to only flushing faeces, urine and toilet paper down the toilet, can reduce the risk of a sewage spill occurring.

If a drain is blocked, it is best to treat it straight away with drain un-blockers or by using baking soda and vinegar. If this does not work it is best to call in a expert.

For trade effluent, it is important that you have an up to date drainage plan which locates all drains and sewers showing where they lead to, knowing what can be put down them.

You should also have sewage spill kits available in case of a such an event. These kits can contain useful tools such as materials to absorb the spill, suction equipment, drain mats and equipment for containing the spill. All staff should be trained or made aware of what to do if a sewage spill were to occur.

Detecting a sewage spill

Whether it be a lot of water flooding or a leak that is slow and drips, it should be looked into as this could be a sign of a sewage spill. Below are other signs that a sewage spill may be present in a property.

Increasing water bills

If you see your water bill shooting up suddenly or gradually increasing over time with no explanation, it is a clear signal of a leak.


An unpleasant smell can give of a sign of a sewage spill. It can be hard to detect where this odour is coming from, but it is an obvious sign that there may be some form of dampness on your property.


Damp patches that are unexplainable, inside or outside the house, can be a sign of a sewage spill. Dampness can bring many other consequences such as mould and mildew, staining, cracked and bubbled surfaces, as well as corrosion.

Low water pressure

If the property’s water pressure seems lower than normal, this can be an indicator that a leak is present. Meanwhile, a high-water pressure can signal that a leak may occur soon due to pipes being burst.

Rodents and pests

Rats and an increase in pests like mosquitos, moths and wood-gnats are all enticed to sewage. Where these rodents and pests are present, can help to indicate where the sewage spill may be.

Sewage spills, whether domestic or commercial should be cleaned up professionally as such specialist companies are trained to deal with the matter safely. It is best to deal with the issue as quickly as possible to stop viruses and gases spreading and keeping away pests and rodents, as well as reducing the damaging effects to a property.

CPL t/a Rainbow International are fully aware of the dangers associated with sewage spills and work quickly to ensure the area affected is thoroughly assessed, decontaminated and cleaned to prevent damage to the environment, businesses and homes. Our sewage clean-up service is comprehensive and ensures any spill is contained and removed safely in a cost-effective manner. Our specialist operatives maintain the strictest level of professionalism throughout and ensure the local environment is protected at all times.

CPL t/a Rainbow International are on hand to provide a rapid response to any emergency sewage spills, so please do not hesitate to get in touch with our friendly team on freephone 0808 196 0363.