Questions
Answers to your questions
Here are the questions owners of country homes ask most often when they first deal with a sewage system of their own. The answers are short and general: the exact solution for your plot comes from the design, and for a working system from its manual and service company.
Almost every worrying question about sewage comes down to two things: what exactly you have noticed and who should check it. Any owner can write down the signs, but only a professional should look inside the installation.
Choosing a system
How does a holding tank differ from a septic tank?
A holding tank treats nothing: wastewater collects in it until a vacuum truck takes it away. In a septic tank, wastewater settles and is partly broken down by anaerobic bacteria; afterwards it usually needs post-treatment, and the sludge is pumped out from time to time.
And a biological treatment plant?
It uses aerobic bacteria that are supplied with air by a compressor. So the plant depends on electricity and needs regular servicing, but it treats the water more thoroughly than a septic tank alone.
Can I choose a system from photos of my plot?
No. Soil type and groundwater level are established by a site survey, and the distances to wells and water intakes are set by sanitary rules and the design. In Russia these are Russian sanitary rules; other countries have their own, so check local regulations and permits. Without these data any advice is guesswork.
When is a pumping station needed?
When wastewater cannot be carried away by gravity, for example if the installation or the sewer network lies higher than the outlet from the house. Whether you need a station is decided by the designer.
Day-to-day use and smells
Where does the smell on my property come from?
There are many causes: an overfilled tank, blocked ventilation, faulty equipment, a damaged lid. Note where and when it smells and call a service company. Do not open manholes or climb into them: dangerous gases, including hydrogen sulphide, can build up there.
What must not go down the drain?
Fats and oils, wet wipes and sanitary products, cat litter, building waste and large amounts of chlorine-based cleaners. Some clog the pipes, others harm the bacteria that septic tanks and treatment plants depend on.
Why has the water started draining more slowly?
It could be a blockage in the house, an overfilled installation or a pump fault. Until the cause is clear, try to use less water and contact a professional.
A warning light has come on at the plant. What should I do?
Check the manual: it usually explains what the signal means. Do not open the lid over the electrical equipment yourself; call the service company and tell them when the signal came on.
Winter and servicing
Do I need to do anything to the system in autumn?
Yes. Book a pump-out in advance, ask the service company about the shutdown procedure if the house will stand empty, and check the hatches and vents from outside. The full sequence is in the practical article on winter.
Can I simply switch the plant off for the winter?
It is best not to do this without the manual and the service company. The procedure differs between systems, and an incorrect shutdown can do harm.
How often is a pump-out needed?
That depends on the system, the number of occupants and how the house is used. The manual gives a guideline, and your own records of past pump-outs give a more accurate one.
Who should I trust with servicing?
A company that knows your system and works on it according to the manufacturer's instructions. Ask what a visit includes and ask for the work done to be written down.
Read next
- Guides
How to get your home sewage system ready for winter, plus the catalogue of practical articles.
- Pumping stations
When wastewater has to be pumped, what a pumping station consists of and how to spot a fault.
- Glossary
Glossary: septic tank, aerobic treatment, pump-outs, post-treatment, site surveys and design.
What this text is based on
- SP 32.13330 "Sewerage. External networks and facilities" (Russian code of practice)
- Russian sanitary rules and standards (general provisions)
- Equipment manufacturers' instructions (general provisions)
Rules, requirements for treatment facilities and equipment manuals are updated from time to time, so the final word belongs to the design, the regulations in force and the documentation of your particular system. The texts here cite Russian standards; other countries have their own building and sanitary rules, so check local regulations and permits. This guide explains how systems work and why decisions are made, but it does not replace a designer, an installer or a service company.