The size of the drain field is determined by how well the ground absorbs water. In places where the ground is hard clay that absorbs water very slowly, the drain field has to be much bigger. A septic system is normally powered by nothing but gravity.he size of the drain field is determined by how well the ground absorbs water. In places where the ground is hard clay that absorbs water very slowly, the drain field has to be much bigger. A septic system is normally powered by nothing but gravity.
Filed Under: Tech & Science, mental health. Every year, about 42.5 million American adults (or 18.2 percent of the total adult population in the United States) suffers from some mental illness, enduring conditions such as depression, bipolar disorder or schizophrenia, statistics released Friday reveal.
Mental disorders were one of the five most costly conditions in the United States in 2006, with expenditures at $57.5 billion. Over 8.9 million persons have co-occurring disorders â that is, they have both a mental and substance use disorder.