Geostatistical Analysis of Scaling and Corrosion Potential in the Lordegan Aquifer

An important aspect of water quality is the potential for scaling and corrosion. The occurrence of either of these two phenomena can increase maintenance costs and shorten the lifespan of the water supply and distribution systems as well as impair water hygiene and aesthetics. The main goals of this study were to evaluate the potential for corrosion and/or scaling of the groundwater of the Lordegan aquifer, and to map relevant indices. For this purpose, data from 32 wells, five qanats and five springs, all located in the Lordegan plain, were used to calculate Langelier saturation and Ryznar stability indices. Kriging interpolation method was used to create maps of the stability indices. Based on the Langelier index, 93 percent of samples had low to moderate potential for scaling and only 7 percent of the samples had high potential for scaling. Based on the Ryznar index, 6 percent of samples had less to moderate corrosion potential and 38 percent of the samples had a high potential for corrosion. In general, due to the presence of carbonatic geological formations, the scaling potential of this groundwater is dominant over its corrosion potential. Based on the Langelier index, 76 percent of the Lordegan aquifer area (i.e. 4500 ha) has low scaling potential and based on the Ryznar index 84 percent of the Lordegan aquifer area (i.e. 5040 ha) has low to moderate corrosion potential. Overall, scaling or corrosion in drinking water and drip irrigation systems does not seem to be a significant problem. These results, however, only pertain to normalwater temperature.