Mound Drainage Field Installation in New Forest, Hampshire
Alton Facility Services completed a raised mound drainage field installation for a private rural property requiring an improved wastewater drainage solution.
The project included excavation, drainage stone, filtered sand, perforated distribution pipework, geotextile membrane, topsoil reinstatement and a small automatic pump chamber connected to the existing treatment plant discharge.
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Project Overview
Alton Facility Services completed a mound drainage field installation in New Forest, Hampshire, for a private residential client requiring an improved wastewater drainage solution.
The works involved the construction of a raised drainage mound, installation of a new drainage field and the addition of an automatic pump chamber to support controlled discharge from an existing wastewater treatment plant.
Our drainage and groundworks team completed the installation using specialist plant, carefully selected drainage materials and a methodical approach designed to protect the surrounding garden and rural setting.
Quick Facts
- Service
- Mound drainage field installation
- Location
- New Forest, Hampshire
- Property
- Private residential / rural
- System
- Existing treatment plant discharge
- Duration
- 5 May 2026 to 12 May 2026
- Outcome
- Raised drainage field and pump chamber installed
The Challenge
The client required a reliable drainage field to support an existing wastewater treatment plant. Due to the site conditions, a traditional below-ground drainage field was not suitable, so a raised mound drainage system was required.
The new drainage field needed to receive treated wastewater in a controlled way and distribute it gradually across the mound. This required the installation of a small automatic pump chamber on the existing treatment plant discharge.
The property was located in a rural setting with garden areas, trees and restricted working space. Careful planning was needed throughout the excavation, installation and reinstatement process.
Site Assessment and Design Approach
The proposed mound drainage field was designed around a 15 metre by 3 metre mound area. The system included a prepared excavation, basal stone layer, graded filter sand, perforated distribution pipework, washed stone, geotextile membrane and a topsoil finish.
A pump chamber was specified to slowly and consistently pump treated water from the existing treatment plant discharge into the new drainage field. This helped provide controlled distribution across the raised mound system.
The design approach allowed the drainage field to be constructed above the existing ground level while still being finished sympathetically within the garden area.
Design Highlights
- 15m x 3m mound footprint
- Three 110mm perforated distribution laterals
- 250mm cut into existing ground
- Graded filter sand and washed gravel layers
- Geotextile separation and topsoil finish
- Pump-fed distribution from the existing treatment plant discharge
The Solution
Alton Facility Services attended site with the required labour, machinery and materials to complete the full drainage installation.
- Excavated an area approximately 3 metres wide by 15 metres long and 250mm deep
- Installed approximately 18 tonnes of 20mm drainage stone
- Built the raised mound using approximately 48 tonnes of filtered sand
- Constructed and laid a new drainage field on top of the sand bed
- Covered the drainage field with approximately 6 tonnes of washed stone
- Installed geotextile membrane to protect and separate the drainage layers
- Encased the completed mound with approximately 25 tonnes of topsoil
- Seeded the finished area to help reinstate the garden
- Created a new access chamber
- Installed a small automatic pump chamber on the existing treatment plant discharge
The Result
The mound drainage field installation was completed in line with the agreed specification.
The finished system provides the property with a raised drainage field designed to work with the existing wastewater treatment plant. Once the seeded topsoil establishes, the mound will settle naturally into the surrounding garden area while continuing to perform its drainage function below the surface.
This project demonstrates Alton Facility Services’ ability to deliver practical drainage field installations, pump chamber installations and wastewater drainage solutions for domestic and rural properties across Hampshire and the surrounding areas.
Drainage Field Installation Photos
These images show the excavation, chamber installation, drainage materials, raised mound construction and reinstatement works carried out during the project.
Services Used on This Project
- Mound drainage field installation
- Drainage field construction
- Pump chamber installation
- Wastewater treatment plant discharge solutions
- Excavation and groundworks
- Drainage stone and sand mound construction
- Geotextile membrane installation
- Topsoil reinstatement and seeding
Need a drainage field, pump chamber or treatment plant discharge solution?
Alton Facility Services supports domestic, rural and commercial wastewater projects across Hampshire, Surrey, West Sussex and surrounding areas.
