Changes in Water Chemistry as a Result of Rainfall Runoff from the Roofs of Various Coatings. Part I / Kształtowanie Się Chemizmu Wód Opadowych W Wyniku Spływu Z Dachów O Różnych Pokryciach. Część I

The aim of the study was to determine the level of calcium, magnesium, sodium, phosphorus and potassium in the waters flowing from the roofs of houses with varying degrees of coverage on the background of their contents in rain waters. On the basis of the Minister of Environment Decree of 24 July 2006 on conditions to be met for the introduction of sewage into the water or ground and on substances particularly harmful to the aquatic environment, runoff from paved areas shall be treated as sewage, and runoff from roofs of buildings are treated as pure water and can be discharged into the environment without a permit. However, literature data indicate the possibility of a significant enrichment of rainwater at the time of contact with the roof covering. The study included 24 roofs of houses or small trade buildings. As background to the research used rainwater collected in two randomly selected locations within the area of research. The study was conducted in areas with low human impact, in order to best capture the effect of the type of roofing material on the formation of water chemistry. Research area was located in the Luslawice in the Tarnow county in Malopolska province. The study included the most common roofs in the surveyed area: cement tile, ceramic tile, bituminous, unpainted galvanized metal, copper and asbestos cement. The tested water samples to determine the content of calcium, phosphorus, magnesium, sodium and potassium. In addition, it was determined the pH value of water and electrolytic conductivity. The results of this study indicate that the water runs off the roofs of respondents in each case contained a greater quantity of the analyzed elements in comparison with rainwater. For example, while the average content of magnesium in the water flowing from the tile cement was almost ten times higher than in rain water, in the case of tile ceramic was almost five times more water from the bituminous coverings contained about three times more magnesium, and water from the galvanized metal contained about six times more as compared with rainwater. Also in the case of most other elements enrichment factors found in the waters cover the cement (tile, and asbestos cement) then galvanized and coated while the lowest were recorded in the enrichment of waters from the roofs of the covering of ceramic tiles. Also noted an increase in the conductivity values in waters from the roofs of the coverings of cement, galvanized steel and ceramic tiles. All runoff from the roofs were of generally higher pH value compared with rainwater, the biggest reaction - about 8 found in the water with cement tiles, slightly lower, about 7.0 in water from roofs with ceramic tiles and sheet copper. pH of the water in the coated sheet was lower than in water, rainwater and oscillating within 5.5. Rainwater pH was 5.94.