What are Package Sewage Treatment Plants?

This is a complete sewage treatment plant in a single unit. Commonly referred to as sewage treatment plants or STP.

They are usually pre-built in a factory and delivered to site. This means installing them is easier than traditional installations. They treat the sewage to a standard that allows the effluent to discharged directly to a watercourse.

The areas we cover include Lincolnshire, Nottinghamshire and Yorkshire, contact us if you would like to discuss your sewage treatment plants needs.

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Sewage Treatment Plant Drainage Surveys

Sewage treatment plants planning, installing, repairing and servicing.

Using high quality drainage survey equipment and our expert knowledge of drainage and building construction we can survey and locate problems. Investigating your septic tank or sewage treatment plant, check your pipework and advise you on the next steps.


  • We carry out inspections to a professional standard which comply with the following:
  • Manual of Sewer Condition classification 5th Edition (2013)
  • The Drain Repair Book 3rd Edition (2011)

How to look after your Sewage Treatment Plants

Sewage treatment plants need to be well maintained to avoid any problems.

Although they reduce the amount of solid waste produced significantly, waste still needs to be regularly removed by a licensed tanker.

Maintenance is typically annually, although this requirement can be more frequent with larger systems.

Croft Drainage Solutions, who use British Water Accredited Engineers have a copy of their: Code of Practice – A Guide for Users of Sewage Treatment Systems to download as a good starting point for information.

Explore drainage regulations

Owner's Responsibilities

As a user of a sewage treatment plants you have a responsibility to make sure that the systems meet the standards set by the regulators.

A correctly designed and installed system will provide a final effluent for discharging that meets these requirements. The environmental regulator has the right to review and vary the discharge requirements. It is therefore essential to regularly maintain and service the sewage treatment plants to make sure it is running efficiently.

There are many simple actions that the owner can take so that the system performs well. The British Water code of practiceA Guide for Users of Sewage Treatment Systems” offers a simple and practical guide to help achieve just that.

British Water Guides

Mr H, Skellingthorpe

“Thanks once again for all your support and work on this project”

The do's and don't of sewage treatment plants


  • Think before putting anything down the sink, toilet or drains
  • Tell users that the drains do not flow into mains drainage but into specialist sewage treatment plants.
  • Read the label and use the manufacturers’ recommended doses for all household cleaning products
  • Use cleaning products little and often so the system isn’t overloaded
  • Use the same washing and dishwasher detergents and other cleaning products. Being consistent helps the bacteria in the system to work more efficiently. If the products in the sewage do not vary widely the bacteria can adapt to remove a wide range of products. But as this can take a while the treatment system will run better if the mixture of products entering it are consistent.
  • Use liquid cleaners for clothes washing and for dishwashers
  • Separately dispose of sanitary towels, tampons, disposable nappies, baby wipes, cotton wool, incontinence pads, etc. Not down the toilet
  • Carry out regular inspections and yearly maintenance in line with the manufacture’s guidelines. To ensure the plant is operating at its optimum
  • Check regularly that the air blower is working by listening for the gentle hum from the plant. Listen for the pump starting and stopping, if one is fitted
  • Ensure that air vents are clear as the plant requires a fresh supply of oxygen
  • Check covers are secure and in good condition
  • Desludge your plant regularly in line with the manufacturer’s guidelines and the level of plant use
  • Check your water hardness and adjusted the amount of household cleaning products you use. In line with the manufacturers’ recommended doses (for example washing machines)


  • Spring clean and use large amounts of cleaners and chemicals in one day
  • Have a “washing day” – spread the washing throughout the week
  • Keep changing the brands of household cleaners and washing powders
  • Tip bottles of medicine, mouth wash, etc. down the toilet. These harm the bacteria in sewage treatment plants
  • Put sanitary towels, tampons, disposable nappies, baby wipes, cotton wool, cotton buds, tampons, baby wipes, rubber products, incontinence pads, etc. down the toilet
  • Over flush the toilet unnecessarily
  • Pour fat, grease or oil from cooking down the sink or drains. We offer a separate grease traps service
  • Allow large quantities of neat disinfectant or bleach into the plant. Use at the minimum concentration possible, as they can restrict the biomass growth within the plant
  • Pour paint, paint thinners, turpentine, white spirit, car engine oil, anti-freeze, brake fluid or garden chemicals down the drains
  • Allow rainwater, groundwater or large volumes of water such as those from swimming pools or Hot Tubs into the sewage treatment plants. Excessive amounts of water will increase the flow rate through the plant and not allow sufficient treatment time
  • Switch off the plant while going on holidays. The plant should operate 24 hours per day, seven days a week
  • Use sink macerators unless the plant is specifically designed for this use. Sink macerators result in additional maintenance
  • Pour everyday products, such as milk, wine or beer, these can increase the organic load on the plant.

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