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.
The data, compiled by the Substance Abuse and Mental Health Services Administration (SAMHSA), also indicate that approximately 9.3 million adults, or about 4 percent of those Americans ages 18 and up, experience âserious mental illnessâ â that is, their condition impedes day-to-day activities, such as going to work.