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Sewage Treatment Plants

Modern systems for properties not served by mains sewers

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Sewage Treatment Plants in Cumbria

Where conventional septic tanks or cesspits don’t comply with discharge regulations—or your site demands higher treatment output—sewage treatment plants (STPs) are the solution. At Unblock Cumbria, we specialise in the design, installation, maintenance, and servicing of sewage treatment plants throughout Cumbria and the Scottish Borders. From homes to commercial sites and rural developments, we deliver compliant, efficient systems built for long-term performance.

We guide you from site survey and system choice through to full sewage treatment plant installation, commissioning, servicing plans, and regulatory compliance. With the right treatment plant in place, treated effluent can be discharged safely into watercourses or soakaways (where permitted), meeting modern environmental standards.

What is a Sewage Treatment Plant?

A sewage treatment plant is a self-contained underground system designed to process and purify wastewater from homes, businesses, or small communities.

Instead of sending waste to the mains sewer, the plant treats the incoming wastewater on site. Through a series of biological and mechanical stages, solids are separated, and the remaining liquid is treated to a standard that allows safe discharge — either to a soakaway system or, where permitted, directly into a local watercourse.

The positioning and design of each treatment plant must comply with Environment Agency (EA) regulations to ensure safe and sustainable operation.

These systems are commonly installed in rural or off-grid properties where there is no access to the public sewer network. They offer an efficient, environmentally responsible, and often more cost-effective alternative to laying long lengths of connection pipework. By treating wastewater on site, a sewage treatment plant reduces infrastructure costs while maintaining high environmental standards.

Our Services

  • Site surveys, soil & percolation tests, and layout planning

  • System design & engineering: aerobic, package plants, MBR, SBR, etc.

  • Installation of clear/clarifier chambers, diffused aeration systems, and final discharge works

  • Commissioning, start-up, and quality checks

  • Maintenance contracts — servicing, pump checks, cleaning, electrical checks

  • Bio-media replacement, aerator servicing, sludge removal

  • Monitoring, compliance reporting, and environmental audits

  • Upgrades, retrofits, and expansions of existing systems

We can recommend the correct system type and size based on occupancy, discharge regulations, topography, and site constraints — ensuring you always install a system suited to your needs.

Why It’s Important

  • Compliance with discharge regulations — Many septic systems no longer meet stringent Environmental Agency or planning rules

  • Higher treatment standards — Treatment plants reduce BOD, ammonia, and suspended solids to safe levels

  • Safe discharge to waters or soakaways — Permitted in many areas when effluent is correctly treated

  • Better long-term resilience — STPs are engineered for performance under variable loads

  • Future-proofing developments — For multi-occupancy housing, commercial premises, or sites with limited soakaway capacity

A well-installed STP offers better performance, compliance, and peace of mind for many years.

Why Choose Us?

  • Full in-house capability — survey, design, install, and maintain

  • Accredited & experienced team in wastewater systems

  • Full regulatory support — permits, discharge consent, and reporting

  • Transparent quotation and design options

  • Support with seasonal management, load variance, and remote sites

  • Maintenance plans to preserve system performance and reduce downtime

  • Local presence across Cumbria & Scottish Borders — quick support when needed

We don’t just hand over the system — we ensure ongoing performance, support, and compliance.

Areas We Cover

We’re proud to serve customers throughout Cumbria and beyond, including:

If you’re unsure whether we cover your location, just give us a call — our friendly team will be happy to help.

Sewage Treatment Plants FAQs

What types of sewage treatment systems are available?

There are several types of domestic and commercial treatment systems, including activated sludge plants, submerged aerated filters, rotating biological contactors and pump-fed systems. Each works differently but all treat wastewater to a much higher standard than a septic tank. We assess your property, usage levels and discharge requirements to recommend the most suitable, compliant system.

How often should treatment plants be serviced?

Most sewage treatment plants need at least one full service per year, although high-use or commercial systems may require more frequent checks. Regular servicing ensures the blower, pumps, diffusers and internal components operate correctly. Routine inspections also help avoid breakdowns, ensure compliance with environmental regulations and extend the lifespan of the system.

Do I need permit or consent to discharge?

In many cases, small domestic treatment plants discharging to ground do not require a permit if they meet the General Binding Rules. However, larger systems, commercial sites or plants discharging to a watercourse may need consent from the Environment Agency. We assess your installation, confirm requirements and guide you through any necessary applications.

What maintenance is required between services?

Most systems require periodic desludging, usually every 12–24 months depending on usage. Homeowners should also keep the blower vent clear, check that alarms work and ensure no harmful chemicals or non-biodegradable items enter the system. Our engineers can provide a simple maintenance checklist to help keep your plant performing efficiently year-round.

What happens if the plant fails?

If a treatment plant stops working, wastewater may not be treated correctly, leading to odours, alarms sounding, poor discharge quality or overflow issues. A failure can often be traced to electrical faults, pump problems or blower issues. We provide rapid diagnosis, emergency call-outs and repairs to get your system running safely as soon as possible.

Can treatment plants handle variable/seasonal demand?

Yes. Many modern treatment plants are designed to cope with fluctuating flows, making them suitable for holiday homes, rental properties or buildings with seasonal occupancy. These systems automatically adjust aeration and treatment processes depending on load. We assess your usage patterns to specify a plant that reliably handles both peak and low-use periods.

Can you replace ageing septic tanks with treatment plants?

Yes. Upgrading an old septic tank to a modern treatment plant is often the best long-term option, especially if your existing system doesn’t meet current discharge regulations. We handle the entire process — from surveys and design to installation, commissioning and regulatory compliance — ensuring your new system performs efficiently and legally.

Get Your Free Quote

Planning to install or upgrade a sewage treatment plant? Call 01900 870 140 or complete our contact form. We’ll assess your site, recommend the right system and provide a fully compliant, high-performance solution tailored to your property.