Drainage & Water System Installation Services

WCI Water & Wastewater engineers install all types of off-mains drainage systems for commercial and domestic properties. Whether it's new builds, replacements, or upgrades, our team can deliver.

The commercial and domestic package plants we install are produced by leading manufacturers including, but not limited to Graf, Klargester, Marsh and FujiClean. Our installations are sized and specified to BS EN 12566 and Environment Agency General Binding Rules, and any electrical connections and commissioning are carried out by our fully qualified Service Engineers.

We carry out both septic tank replacements and new septic tank installation, including drainage field design to BS 6297:2007+A1:2008 compliance. This includes replacing failed tanks and drainage fields, and emergency installs where time is critical. Percolation testing is conducted before specification to confirm soakage rates, ensuring a smooth installation.

Our in-house Consulting Engineers where package units are not suitable designs and builds our bespoke pumping stations. However, we can provide package pumping station supply and install where gravity drainage is not possible. We’re also experienced with submersible vortex and grinder pumps, progressive pumps and rising main design.

We design, install and commission private water supply systems, including borehole drilling coordination, spring and surface water abstractions, and mains-fed booster systems. Installations include filtration, UV disinfection, iron and manganese removal, and pH correction to ensure water is safe for drinking, washing and process use. All systems are installed in line with the Private Water Supplies Regulations, with water quality testing through our UKAS-accredited laboratory partner to confirm compliance before handover.

A reedbed installation provides a natural, low-energy solution for secondary and tertiary wastewater treatment, ideal for rural properties, campsites and sites with restricted power access. Designed to BS 6297 and Environment Agency guidance, our reedbeds are sized according to population equivalent and site conditions, using appropriate liner systems and planting to ensure long-term treatment performance.

We supply and install rainwater harvesting systems for domestic and commercial properties, capturing roof water for non-potable uses including toilet flushing, garden irrigation and vehicle washing. Systems are sized to catchment area, storage capacity and anticipated demand, with below-ground and above-ground tank options available. Installations are commissioned by our in-house Service Engineers to ensure reliable, low-maintenance operation from day one.

We have full groundworks capability, including excavation, bedding, site clearance, and reinstatement. We are praised for our quality,  programme control and reinstatement with care.

When homeowners, developers and businesses engage our WCI Water 7 Wastewater engineers for an installation, we often see four common scenarios.

We work alongside architects, self-builders and developers to ensure the right solution. If a mains sewer connection is not available or viable on a new build property, our in-house capability means we can provide a designed and permitted off-mains system from day one.

The most common reason homeowners contact us is for septic tank replacement after a compliance survey reveals a non-compliant system. Where a failed or non-compliant drainage field or sewage treatment plant needs replacing, we can find the right solution quickly. Our survey process establishes the right solution, including EA permit requirements where needed.

Our in-house Consulting Engineers handle permit applications as part of the installation service. We understand that in the event of an Environment Agency notice or General Binding Rules breach, urgent action is required.

A drainage compliance survey before a property exchange usually reveals a non-compliant system that needs  replacing before a sale can conclude. WCI survey, specify, install and certify, keeping completions on track.

Whether you're building a new home requiring private drainage, replacing a failed septic tank, connecting to mains sewers or installing treatment infrastructure for a commercial development, our installation services deliver compliant, functional systems that work reliably from day one.

Installing drainage and water systems requires Building Regulations approval. Professional installation meeting Approved Document H standards ensures your system passes inspection and receives completion certification.

DIY or poorly executed installations fail within years - wrong system specification, inadequate drainage fields, incorrect depths, poor ground preparation. We’ve seen (and fixed) it all, professional installation gets it right first time, avoiding the expense of remedial work.

How a system is installed determines how long it lasts. Proper bedding, backfilling, connection sealing and installation details make the difference between decades of reliable service and premature failure.

As part of WCI Group, our Project Engineers work alongside Consulting Engineers who design systems. This integration means installations reflect design intent accurately with no lost-in-translation problems between designer and installer.

As experienced sewage treatment plant installers with over 40 years in the field, our engineers have extensive knowledge of ground and drainage conditions across Somerset, Devon, Dorset and Cornwall.

We're not general groundworkers who happen to install drainage - we're wastewater specialists. Our engineers understand how systems work, why design details matter, and what affects long-term performance.

When WCI designs your system, installs it and maintains it long-term, there's nowhere to hide. If problems occur, we fix them – full accountability. One company, complete responsibility.

Because WCI Service Engineers maintain systems for decades, our Project Engineers install with maintenance in mind - access for desludging tankers, rodding points for blockage clearing, electrical panels positioned for safe servicing. We design and build systems that can actually be maintained.

Every installation starts with professional site survey. We assess ground conditions, access constraints, and site-specific requirements before specifying appropriate systems and providing comprehensive written quotations with no hidden extras.

Across the group, we hold accreditations and certifications, including British Water, SSIP, CHAS, SafeContractor, and ICE.

With WCI, you’ll receive end-to-end capability, including survey, design, permitting, installation and commissioning under one contract. We leave no gaps in accountability and no coordination overhead.