Risk Assessment of Water Intakes in South-Eastern Poland in Relation to the who requirements for Water Safety Plans
tải về 1.26 Mb. Chế độ xem pdf
|
| Figure 3. The flood risk map for a fragment of the indirect protection zone of Intake C.
4. Discussion of Results and Assessment of the Need to Establish or Adapt Water Pro- tection Zones The water quality of rivers, which are the source of water supply, is threatened by adverse events related to the discharge of untreated municipal wastewater (Event 6) and, to a lesser extent, by agriculture (Event 4). This is due to the fact that some of the areas located in the catchment area of these rivers still do not have sewage systems (sewage systems in communes is at the level of approximately 70%), which, in the absence of the control of invoices for waste disposal, means that residents often discharge sewage into the ground or a ditch. According to administrative units, eutrophication caused by pollu- tion from municipal sources is the most significant threat to a high-quality water status in the Podkarpackie Province in Poland. For this reason, the ammonium nitrogen content is a very important indicator of water quality. The content of individual nitrogen ionic forms present in the water (ammonium NH 4+ , nitrate NO 3– and nitrite NO 2 ) and the assessment of their variability over time, along with correlation with the data on land use in the vi- cinity of the intake, allows for an approximate assessment of the time and possible origin of the pollutants. The ammonium ion found in water intended for human consumption may come from anthropogenic pollutants entering the intake (mainly surface intakes). The source of threats may be a situation where water pollution (sewage, natural and artificial fertilizers, rainwater runoff and leachate from landfills) causes microbiological contami- nation of the water or penetration of the water by toxic chemicals. The ammonium ion is not the cause of the danger here, but it does signal risk. In the winter season, when both vegetation and nitrification are inhibited, the values of ammonium ion concentrations show an upward trend (Event 10). The greatest threats are periodic increases in turbidity and water blooms causing, among others, the necessity for the frequent rinsing of filters (Event 9). Very high turbidity (even 3000 NTU) is often associated with the occurrence of flood water flows (Event 7). In the analyzed time period (10 years), water intake was continuous, and the water treatment plant worked continuously, pumping water to the water supply network in compliance with the regulation from the Polish Minister of Health on 7 December 2017 on the quality Figure 3. The flood risk map for a fragment of the indirect protection zone of Intake C. Based on the performed analysis for the water in Intake C, it can be concluded that flooding does not cause a significant threat to the analysed intake. However, the operator of the water supply system should have a response plan in the event of flooding and the related water quality deterioration, which causes a threat to the continuity of the water treatment process. The analyzed system has another two independent water intakes, so in the case of flooding, they can compensate for the water production of Intake C. Another option to ensure the supply of water is to determine the possibility of water supply from outside sources (water intake from public wells, water trade with neighboring municipalities). tải về 1.26 Mb. Chia sẻ với bạn bè của bạn:
|