Most Kenyan properties are not connected to a public sewer. According to the 2019 Kenya Population and Housing Census, as reported in the government’s sanitation policy, only about 9.7% of households nationally used a main sewer (24.6% in urban areas and 0.3% in rural areas). About 9.2% used septic tanks. For homes, schools, hotels, apartments and commercial developments beyond the sewer network, a correctly designed and maintained on-site system is essential for health, for the environment and for the value of the property.
In February 2026 the government launched the National Sanitation Management Policy. This guide explains what the policy means for property owners, and what good septic and wastewater management looks like in practice.
Why sanitation matters
Poorly managed wastewater spreads disease, contaminates boreholes and wells, pollutes rivers and creates smells and nuisances that lead to disputes with neighbours and with county authorities. A failing septic system can also be expensive to put right once it has saturated the ground or damaged foundations. Good sanitation protects the people on the property, their neighbours and the water sources everyone depends on.
Kenya’s National Sanitation Management Policy
On 27 February 2026, the Ministry of Water, Sanitation and Irrigation launched the National Sanitation Management Policy, published as Sessional Paper No. 7 of 2024, under the theme “Towards Safely Managed Sanitation for All by 2030 and Beyond”.
The policy covers both sewered and non-sewered sanitation across the whole sanitation service chain: containment, emptying, transport, treatment, and safe disposal or reuse. It notes that almost 90% of Kenyans rely on non-sewered (on-site) sanitation. For on-site systems, the policy measures include commitments to:
- develop and implement guidelines, regulations and standards for on-site sanitation, faecal sludge management and decentralised wastewater treatment;
- ensure containment facilities are designed and built for safety, ease of emptying and protection of water resources and public health;
- ensure that owners of non-sewered facilities that cannot treat faecal sludge on site regularly empty them, and safely transport the sludge to a treatment facility;
- regulate, train and equip emptiers, and develop standard operating procedures for safe emptying and transport;
- establish licensing or permitting for faecal sludge management service providers;
- map and assess septic tanks and pit latrines;
- ensure that effluent discharged from domestic settings meets NEMA, WRA and public health standards.
Policy direction versus legal requirements
This distinction matters. A sessional paper sets government policy and direction. Many of its measures will take effect through new or amended laws, regulations, county by-laws, standards and guidelines, which the policy itself says will implement it. At the time of writing, property owners should treat the policy as a clear signal of where regulation is heading: more oversight of septic systems, emptying and sludge disposal. It does not on its own create detailed new obligations.
Obligations that already apply include:
- county planning and building approval for new developments, including their sanitation arrangements;
- public health law, which prohibits nuisances such as overflowing sewage;
- the Environmental Management and Co-ordination Act and its Water Quality Regulations (2006), which control the discharge of effluent into the environment, enforced by NEMA.
Confirm the current requirements for your project with your county government and NEMA.
Planning a septic system
A conventional septic system has two main parts:
- The septic tank: a watertight, usually multi-chamber tank where solids settle as sludge, grease and scum float, and partial treatment takes place.
- The effluent disposal or treatment stage: a soakaway, drainage field or further treatment unit that disposes of, or treats, the liquid leaving the tank.
Planning starts with:
- the number of users and daily wastewater flow, including kitchens and laundries;
- soil and percolation conditions, which show how well the ground can absorb effluent;
- groundwater level and nearby water sources;
- available space, slopes and access for desludging trucks;
- plans for future extensions and connection to sewer if one is built.
Wastewater treatment options
- Septic tank with soakaway or drainage field: suitable where soils absorb well and groundwater is deep.
- Bio-digester and package treatment units: compact systems that provide more treatment than a basic septic tank, useful on tight plots. Performance depends on correct sizing and maintenance.
- Decentralised treatment plants: for estates, hotels, schools and commercial developments. Treated effluent can sometimes be reused for irrigation or flushing, subject to the applicable standards.
- Conservancy (holding) tanks: where no on-site disposal is possible, emptied regularly by licensed operators.
The right option depends on the site, the volume and the discharge route. One size does not fit all.
Design considerations
- Watertight construction: leaking tanks contaminate soil and groundwater.
- Correct sizing: undersized tanks pass solids into the soakaway and clog it.
- Inspection chambers at changes of direction and junctions, with secure, child-safe covers.
- Ventilation to release gases safely.
- Access for emptying: covers that can be opened safely, and a route for the exhauster truck.
- Separation from water sources: boreholes, wells, tanks and streams. Distances should be set by a qualified professional and checked against county requirements. See our borehole guide for why this matters.
- Grease traps for commercial kitchens.
Inspection and maintenance
- Inspect tanks and chambers periodically for sludge and scum levels, cracks, blockages and odours.
- Keep fats, oils, wipes, sanitary products, nappies and chemicals out of the system.
- Do not drive heavy vehicles over tanks or drainage fields unless they are designed for it.
- Keep records of inspections and desludging.
Safe desludging
Sludge accumulates over time and must be removed before it fills the tank and is carried into the soakaway. How often depends on the tank size and the number of users, so measure the sludge rather than waiting for an overflow.
- Use a licensed exhauster operator who discharges at an approved treatment or disposal facility. Illegal dumping pollutes the environment, and the policy specifically targets it.
- Never enter a septic tank. Septic tanks can contain toxic gases and too little oxygen, and these can kill quickly. Manual emptying and confined-space entry must only be done by trained, properly equipped workers.
- Do not use chemicals or additives to “dissolve” sludge in place of desludging.
Environmental protection
A working system keeps pathogens and nutrients out of groundwater, streams and drains. Any effluent discharged above ground, or into drains or watercourses, must meet the applicable standards. Untreated discharge is an offence and a health hazard.
Common septic failures
- Overflowing or backing-up drains: often a full tank, a blocked inlet or a clogged soakaway.
- Persistent smells: poor ventilation, broken covers or leaks.
- Wet, green or sunken ground over the drainage field: the soakaway is failing.
- Contaminated borehole or well water: the system is leaking or too close to the source.
- Cracked tanks or collapsed covers, which are both a pollution risk and a safety risk.
When to seek professional help
- When planning a new development or extension, so that the system is designed and approved correctly.
- When you see any of the failure signs above.
- Before buying a property that relies on on-site sanitation.
- When the number of users increases, for example a new hostel block, more apartments or a larger restaurant.
- When there is a borehole or well on or near the property.
How Weber Works can help
Weber Works Ltd designs, builds and rehabilitates wastewater and septic systems for homes, institutions and commercial properties. We can inspect existing systems and recommend practical improvements.
This article is general information as at the review date shown. It is not legal advice or a design for your site. Always confirm requirements with your county government and NEMA.
