There is truth to this. I have included a link that states many of the things that can cause problems with septic systems.
http://74.6.239.67/search/cache?ei=...ptic+tanks+tank&d=YaycOUxIStea&icp=1&.intl=us
http://74.6.239.67/search/cache?ei=...ptic+tanks+tank&d=YaycOUxIStea&icp=1&.intl=us