Off-Mains drainage services
Professional drainage surveys, percolation testing and private drainage system assessments for rural homes, developments and properties not connected to the mains sewer.
Clearflow Surveys helps homeowners, architects, developers, estate agents and drainage contractors understand, inspect and evidence off-mains drainage systems. From septic tank surveys and treatment plant investigations to percolation tests for planning applications, we provide clear reports and practical advice.
What we do
Septic tank & Wastewater treatment plant surveys
We inspect septic tanks and private drainage systems to assess their condition, layout, discharge route and visible signs of failure. Ideal for homebuyers, property owners, rural homes and older off-mains drainage systems.
We inspect: inlet pipework condition, tank condition and functionality, outlet pipework condition and outfall arrangement. You receive a clear written report with our findings and recommendations.
Percolation tests
We carry out percolation tests to assess how quickly water drains through the ground and whether the site is suitable for a drainage field, soakaway or off-mains drainage design. Ideal for planning applications, replacement treatment plants, new rural developments and surface water drainage proposals.
We test: ground conditions, trial hole locations, water infiltration rates, drainage field suitability and soakaway performance where required. You receive a clear written report with our findings, test results, photographs and recommendations.
Who we help
We work with anyone responsible for a property or project that is not connected to the mains sewer.
Homeowners: For rural properties, older homes, drainage problems, septic tank replacements and treatment plant upgrades.
Homebuyers: For pre-purchase drainage surveys where the property has a septic tank, cesspit, treatment plant or unknown private drainage system.
Architects and planning consultants: For planning applications that need drainage evidence, percolation testing or support for off-mains drainage proposals.
Developers: For new-builds, barn conversions, rural developments and sites where foul or surface water drainage needs to be assessed.
Estate agent and solicitors: For property transactions where private drainage needs to be checked, evidenced or better understood.
Drainage contractors and installers: For independent surveys, testing, reporting and investigation before or after installation works.
Why choose Clearflow Surveys?
1) Survey-led, not sales-led
We are drainage survey specialists. Our role is to investigate, test and report clearly, not to push unnecessary installation work.
2) Clear reports you can actually use
Our reports include photographs, observations and practical recommendations for homeowners, consultants, contractors and planning teams.
3) Practical drainage knowledge
We understand how private drainage systems work on real sites, including older rural properties, septic tanks, treatment plants, drainage fields and soakaways.
4) Support for planning and property decisions
Whether you are buying, building, upgrading or investigating a problem, we help you get the information needed to move forward.
5) Local North West coverage
Based in Cheshire, we support domestic and development sites across the North West.
6) Trusted partner network
Where remedial work is needed, we can recommend trusted contractors while remaining focused on independent surveying and reporting.
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Off-mains drainage refers to properties that are not connected to the public sewer and instead use private systems such as septic tanks, cesspits, package treatment plants or drainage fields.
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Yes, it is strongly recommended. A survey can help identify the condition, layout and potential issues with the private drainage system before you complete the purchase.
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A septic tank separates solids from wastewater and usually discharges to a drainage field. A package treatment plant treats wastewater to a higher standard before discharge, depending on the system and site arrangement.
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You may need one if the property cannot connect to a mains sewer and the proposed drainage system relies on discharge to ground or a drainage field.
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Yes. We can use drainage investigation methods such as CCTV surveying, tracing and site inspection to help locate drainage runs, chambers, tanks and discharge routes.
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If a drainage field has failed, the system may need further investigation, redesign or replacement. We can inspect the site, record the issues and advise on practical next steps.
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Clearflow Surveys focuses on surveys, testing and reporting. Where installation or remedial works are needed, we can pass the work to trusted contractor partners.
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We are based in Cheshire and cover the North West, including surrounding towns, rural areas and development sites.
Frequently Asked Questions
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