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Treatment Plant Installation

Domestic, Rural and Commercial Sewage Treatment Plant Installation

AFS installs sewage treatment plants for homes, rural properties, estates, farms, hospitality premises, managed sites and developments that need a new or replacement off-mains wastewater system.

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Complete sewage treatment plant installation support

A treatment plant installation must be correctly specified, installed and connected to avoid compliance issues, odours, poor discharge or future breakdowns.

Alton Facility Services installs domestic and commercial sewage treatment plants across Hampshire, Surrey, West Sussex and nearby areas. We support rural homes, estates, farms, commercial sites and development projects requiring private drainage.

Works may include excavation, plant installation, inlet and outlet drainage, final effluent discharge arrangements, drainage field or watercourse connections, electrical coordination, commissioning and reinstatement.

We can advise where an existing septic tank needs replacement because it is non-compliant, failing, discharging incorrectly or unsuitable for the property usage.

Each site is different. We check ground conditions, levels, access, discharge route and power. We also consider tanker access, building control and environmental requirements.

New treatment plants

Installation of package sewage treatment plants for off-mains properties.

Septic tank replacement

Upgrade from old septic tanks to compliant sewage treatment systems.

Groundworks and connections

Excavation, pipework, chambers, discharge routes and reinstatement.

How treatment plant installation works

Site review

We assess levels, access, discharge route, existing drainage and likely plant position.

Specification and quote

We advise on the practical installation scope and provide a clear quotation.

Install and commission

AFS installs the plant, connects drainage and completes practical handover checks.

Choosing the right private drainage system

The correct system depends on the property, usage and discharge route.

A sewage treatment plant may be suitable when a septic tank is no longer compliant. It can also improve discharge quality or support a new off-mains system.

The installation must consider population equivalent, ground conditions, discharge consent or General Binding Rules, drainage field suitability, maintenance access and tanker emptying access.

Important design factors

  • Number of bedrooms or users
  • Discharge to drainage field or watercourse
  • Ground conditions and levels
  • Power supply and alarms
  • Access for installation and emptying
  • Ongoing service requirements

From excavation to commissioning

AFS combines drainage knowledge with civils and installation experience.

The physical installation often involves excavation, tank bedding, anchoring where needed, backfill, inlet drainage, outlet pipework, inspection chambers and reinstatement.

Once installed, the plant needs commissioning and future servicing. A poorly installed treatment plant can suffer from settlement, poor falls, ingress, flooding, poor discharge quality or repeated alarms.

Installation scope can include

  • Excavation and tank placement
  • Inlet and outlet pipework
  • Inspection chambers
  • Drainage field or discharge connection
  • Reinstatement
  • Maintenance advice and handover

Treatment-plant installation evidence

Completed AFS works showing treatment-system installation, excavation, connected drainage and discharge infrastructure.

New non-electric treatment system installed at an Oxted property New non-electric treatment system installed during the Oxted wastewater upgrade. Excavated drainage trench for treatment-system discharge works in Oxted Excavation and drainage work forming part of the Oxted installation. Automatic chamber installed for a treatment plant discharge system in the New Forest Automatic pump chamber connected to an existing treatment-plant discharge in the New Forest.
View the Oxted wastewater upgrade →

Sewage Treatment Plant Installation details

When a new treatment plant is needed

A new plant may be needed when a property has no mains drainage connection. It may also be required when an old septic tank is failing or no longer compliant.

We first review the property, expected flows, ground conditions and discharge route. This helps us recommend a system that is practical to install and maintain.

What the installation can include

  • Site survey and level checks
  • Treatment plant sizing and selection
  • Excavation and tank placement
  • Inlet, outlet and chamber connections
  • Electrical coordination and alarms
  • Commissioning, testing and handover

AFS can also support septic tank conversion, treatment plant maintenance and tanker services.

Plan for future maintenance

Good access is important after installation. The plant must be serviceable, and a tanker must be able to reach the system when desludging is required.

Call 01420 561661 or use the enquiry form to discuss the property, postcode and existing drainage.

Recent treatment plant jobs and updates

Work our engineers and crews have finished recently, from our own job updates.

Replacement Sewage Treatment Plant Installation Completed in Farnham Replacement Sewage Treatment Plant Installation Completed in Farnham Mike standing on the grate of a Klargester BioDisc sewage treatment plant in Shepperton Klargester BioDisc Component Repair in Shepperton Treatment Plant Service in Liphook Finds Split Diaphragms Treatment Plant Service in Liphook Finds Split Diaphragms
See all our latest jobs →

Check we cover your area

We cover about 50 miles around Alton. Type the first part of your postcode and we will tell you the nearest town we cover, how far it is from Alton and whether it is inside our area.

The first part is enough, for example GU34. We use it only to work out the distance from Alton and we do not keep it.

Enter the first part of your postcode, for example GU34.

Contains OS data © Crown copyright and database right 2026
Contains Royal Mail data © Royal Mail copyright and database right 2026
Contains National Statistics data © Crown copyright and database right 2026

Sewage treatment plant installation areas

Explore local installation information for homes, estates, commercial sites and off-mains properties across our principal coverage areas.

HampshireGuildfordBasingstokeAltonChichesterWinchesterSurreyLiphook

Related private drainage services

Treatment plant installation connects closely with septic conversion, maintenance and tanker services.

Septic Tank ConversionSewage Treatment PlantsTreatment Plant MaintenanceSewage Tanker ServicesPackage Pump StationsDrain InstallationsOxted treatment-system installationNew Forest treatment-plant discharge projectFarnham Klargester Installation Project

Request Sewage Treatment Plant Installation advice or a quote

Send the details through and a member of the AFS team will come back to you.

Sewage Treatment Plant Installation FAQs

Can you replace an old septic tank with a treatment plant?

Yes. AFS can advise on replacement of old or non-compliant septic tanks with suitable treatment plant systems.

Do you handle the excavation?

Yes. We can undertake the groundworks, tank installation, pipework, chambers and reinstatement as part of the installation scope.

Do sewage treatment plants need servicing?

Yes. Treatment plants need routine maintenance to keep the biological process and mechanical components working correctly.

Do I need permission?

That depends on the discharge route and site circumstances. We can advise what information is usually needed and when specialist approval may be required.

How much does a domestic sewage treatment plant cost?

Cost depends on design flow, ground conditions, excavation depth, access, discharge route, electrical supply, pipework, commissioning and reinstatement. AFS can review the property information and arrange the survey needed for a site-specific proposal.

How long does sewage treatment plant installation take?

The installation programme depends on site survey information, permissions, equipment lead time, excavation conditions, weather, access and the discharge arrangement. These stages should be confirmed before a start date is agreed.

Need help with sewage treatment plant installation?

Send an enquiry or call the AFS team. We’ll confirm the practical next step and whether a site visit is needed.

Call 01420 561661