If your property is not connected to the mains sewer, you will need an alternative way to treat wastewater safely and in line with current regulations. One option you may have come across is a STP, also known as a Sewage Treatment Plant (sometimes also called a Package Treatment Plant).

In this blog, we explain what a STP is, how it works, and whether it could be the right solution for your home.

What does STP stand for?

STP stands for Sewage Treatment Plant. It is a compact, self-contained wastewater treatment system designed for individual homes or small groups of properties. Unlike a septic tank, a Sewage Treatment Plant actively treats wastewater before it is discharged. This produces much cleaner water and helps properties meet modern environmental standards.

How does a Sewage Treatment Plant work?

A Sewage Treatment Plant treats wastewater in several stages using natural biological processes.

In simple terms:

• Wastewater from your home flows into the treatment plant
• Solids are broken down by naturally occurring bacteria
• Air is introduced to support the treatment process
• Cleaned water is discharged safely to a watercourse or soakaway, subject to permissions
  

The system is sealed, compact, and designed to operate continuously with minimal involvement from the homeowner.

STP vs septic tank. What is the difference?

Many homeowners assume septic tanks and treatment plants work in the same way. They do not.

A septic tank mainly separates solids from liquids. It does not fully treat wastewater.
A Sewage Treatment Plant treats wastewater to a much higher standard before discharge.

This difference is increasingly important. Environmental regulations have become stricter, and many older septic tanks no longer meet compliance requirements.

When do homeowners need a Sewage Treatment Plant?

A STP is often recommended if:

• Your property is not connected to mains drainage
• You need to discharge treated water to a ditch, stream, or river
• Your existing septic tank does not comply with current regulations
• You are building a new home or converting a rural property
  

Since the General Binding Rules were introduced, many homeowners have needed to upgrade their drainage systems. Installing a Sewage Treatment Plant is one of the most effective long-term solutions.

Is a Sewage Treatment Plant better for the environment?

Yes. One of the biggest benefits of a STP is its environmental performance.

Because the wastewater is properly treated, a Package Treatment Plant:

• Produces significantly cleaner discharge water
• Reduces the risk of pollution
• Helps protect rivers, groundwater, and local wildlife

For homeowners who want a more environmentally responsible solution, a STP is often the preferred choice.

Does a STP need electricity?

Most Sewage Treatment Plants require a small electrical supply to power the aeration process. Running costs are generally low, and modern systems are designed to be energy efficient. Binder always explains expected running costs clearly before installation.

How much maintenance does a STP require?

Like all wastewater systems, a Sewage Treatment Plant needs regular maintenance to keep it operating correctly. This usually includes:

• Routine servicing
• Sludge removal at recommended intervals
• Periodic checks to ensure the system is functioning properly
  

With the right servicing plan in place, most homeowners find a STP reliable and straightforward to manage.

Is a Sewage Treatment Plant right for your home?

A STP can be an excellent solution, but it is not the right choice for every property. The most suitable system depends on:

• The size of the property and number of occupants
• Ground conditions
• Discharge location
• Local environmental requirements
  

This is why a proper site assessment is essential before making a decision. We provide a site survey free of charge to any new residential customers. 

Speak to Binder for clear, honest advice

If you are unsure whether a Sewage Treatment Plant is right for your home, getting professional advice early can save time, cost, and stress. 

Our team provides straightforward guidance, compliant installations, and ongoing support for homeowners. Contact us on 01473 830582 to discuss your property and find the right wastewater solution for you.