Not every house can be connected to the sewage system, which is often a big problem – what to do with the waste? Until recently the most popular solution was the septic tank, which has recently been losing popularity in favour of domestic sewage treatment plants.
What is domestic sewage treatment plant?
Household sewage treatment plant is an alternative to septic tank and sewage system. This form of sewage disposal is best suited for large plots, because it takes up a lot of space and during its installation distances must be kept from:
- plot boundary 2 m,
- wells 15 m,
- telecommunication cables 1 m,
- electric cables 0.8 m,
- water mains and gas lines 1.5 m
- road 2 m,
- water reservoirs 15 m,
- from bushes and fruit trees 3 m,
- from windows and external doors of a residential building 5 m.
Types of sewage treatment plants
There are different types of sewage treatment plants, depending on the sewage treatment method:
- drainage and infiltration,
- with sand filter,
- ground and plant-based
- with active sludge,
- with biological deposit.
Household sewage treatment plants in light of the law
Act of 7 July 1994. – Construction Law, Journal of Laws of 2019, item 1186 as amended, article 29, section 1, point 3, article 30, section 1, point 1 specifies that a domestic sewage treatment plant with a capacity of up to 7.5m3/day requires only a notification at the appropriate city office or county district office. If the throughput exceeds 7.5m3/day, then a construction permit is required.
Domestic treatment plants with a capacity of up to 5m3/day do not require a water permit to discharge wastewater into water or soil
If the capacity of a domestic sewage treatment plant exceeds 5m3/day, then a permit is required for the construction of the water facility and for the discharge of sewage into water or onto land – regardless of where it is discharged.
If the wastewater is discharged into the ground, waters or devices that are not owned by the investor, then a water permit is required regardless of the capacity of the treatment plant – Act of 20 July 2017. – Water Law, Dz.U. of 2020 item 284.
>> See also: What does the construction of a domestic septic tank entail?
Advantages of a domestic sewage treatment plant
Domestic sewage treatment plant has many advantages:
- high savings – the costs of sewage treatment plant pay for itself already after 3 years of use. In the following years the cost is similar to that of a septic tank;
- ease of use – the only thing you need to provide to the sewer system are special bacteria and enzymes, as well as periodical removal of sludge;
- ecology – when using such a wastewater treatment plant, you can be sure that the wastewater does not pollute the soil
- versatility – it can be used regardless of the terrain and soil type. Household sewage treatment plants do not need to be insulated – they work flawlessly regardless of weather conditions.
- durability – tanks are manufactured in such a way that atmospheric factors do not have a negative impact on their operation. Most tanks have a two-year warranty;
- receiving a partial refund of costs – the amount of funding is up to 80% of the investment;
- no unpleasant odours –no unpleasant odours escape from the household treatment plant. There is also no possibility of overfilling, as in the case of a septic tank.
Disadvantages of household sewage treatment plant
Domestic sewage treatment plant has also some disadvantages, these are:
- price – the cost of building a domestic sewage treatment plant ranges from 6 to 20 thousand PLN;
- the need to periodically add bacteria and clean the tank – for some users this can be inconvenient;
- space – the treatment plant can only be built on a large plot of land where it will be possible to keep the distance;
>> Read also: Material and capacity of the septic tank – how to choose the right one?
Cost of construction and operation of domestic sewage treatment plant
Total cost of construction (material and labor) of domestic sewage treatment plant for a house with maximum 5 residents, depending on the type of treatment plant, is
- with an infiltration drain: pLN 6 000 – 8 500,
- hydrobotanic: 12 000 – 18 000 PLN,
- biological bed: pLN 6,500 – 22,000,
- with active sludge: pLN 11,000 – 18,600.
The cost of operation is 170 – 200 zł/year. This price includes:
- the cost of removing sediment from the clay settling tank,
- purchase of bacterial preparations