In early April, the Idea 3W effort published a report on the status, equipment and procedures at the catchment stations. This is an important topic in the field of distributed utility management. In Poland, 72% of the population uses sewerage, according to the Central Statistical Office. The households of the remaining 28% therefore have no direct connection to the treatment plants. Thus, a sewage truck, or septic tanker, and a sewage collection point, or catchment station, are needed to deliver the generated wastewater. The report, compiled by Ścieki Polskie and Bank Gospodarstwa Krajowego, deals precisely with the state of the points where sewage pumped out by septic tanks enters the treatment plant. Based on CSO data and the report, it can be concluded that as much as 93% of wastewater from septic tanks and domestic wastewater treatment plants does not go to catchment stations. The problem with diffuse municipal pollution is therefore significant.
Status of the catchment stations
At the outset, it should be noted that the information presented in the report is based on the results of a survey to which 383 stations responded, or 16% of the total. The conclusions are extended to all stations, but it is possible that the real situation is not painted in such dark colors as the report portrays it.
The first conclusion is that 89.3% of the stations surveyed do not comply with the requirements of the Regulation of the Minister of Infrastructure on the conditions for introduction of liquid wastes to the waste disposal stations. In general, there is a lack of adequate wastewater collection and monitoring procedures. The biggest problem is equipping such facilities with solids separators. They are missing from more than 45% of the stations surveyed. The separators are supposed to stop m. in thrown into the toilet seat items that should not go there, such as diapers. On top of that, 12% of the catchment stations do not measure the volume of wastewater received, and 13% of the stations record leaks in the process line. Nearly 90% do not keep records of the waste they collect, and some do not even confirm receipt.
In terms of wastewater composition testing, which is not required by law, only pH is commonly measured. Half of the stations also measure temperature. Tests for characteristic parameters of municipal wastewater, such as BOD5, or biochemical oxygen demand, and COD, chemical oxygen demand, are indicators monitored at 40% and 43% of stations, respectively.
Conclusions of the report
A picture of underinvested and outdated catchment stations emerges from the report compiled by BGK and Wastewater Poland. A lot of work and a whole series of changes are still needed to organize wastewater management outside agglomerations, where there are no sewers. Sink stations should certainly be the start of this, as a link to the wastewater treatment plant. Polish Wastewater and BGK plan to select one catchment station and carry out a model upgrade in the near future, so as to set the course of technological development for these facilities. The project’s results, both environmental and economic, are to be made public as educational and instructional material for wastewater treatment plant operators.