We get a lot of questions about clean sand. Most are related to the clean sand requirement for mound sewage treatment systems. However, we do get questions about using sand in either single- or multiple-pass sand filters and use of sand or other materials as fill or final cover for soil treatment systems.
In this column, we focus on clean sand for mound treatment systems. In Minnesota, there are more than 50,000 mounds in operation. When designed and installed correctly, these are effective and long-lasting systems. Some have been in continuous operation since the 1970s. This type of success requires use
