In the USA, all laws regarding septic systems are local. Federal guidelines are just that and all states use their own standards and rules to set minimum standards. Rules such as how big the septic drainfield must be are usually determined on a state-wide level by state departments of health. The state sets minimum standards, but no county can be less restrictive than the state guidelines, only more restrictive. State guidelines vary widely from state to state. County health departments or health districts set minimum standards and publish these to regulate local construction of individual septic systems. When commercial or community septic systems exceed a certain capacity (usually determined in gallons per day,) state rather than local jurisdiction may take over. Because the USA contains hundreds of local health departments some with hundreds of rules, there is no central resource for the setting or approving of standards. This makes it difficult for new ideas in septic design to be introduced and approved because of the hundreds of local approvals required. For this reason it is becoming increasingly difficult for homeowners to avoid the use of specialized septic engineers or soil scientists in the design of systems. With increasing attention to environmental protection these days, the design, construction and operation of septic systems is becoming more of a hot issue with lots of misinformation out there. Septic systems are proven to be as safe and effective as municipal sewage treatment. However, many state governments have discovered that passing arbitrary and unscientific laws restricting the design and use of septic systems can be an effective way of controlling rural growth to the benefit of urban populations. This is possible due to the increasing proportion of people living in cities and a lack of general knowledge in the public about the "potential" public health hazards associated with the workings of the mysterious septic system. As a result septic systems are becoming more expensive and more difficult to get approved. Without an approved septic system that meets or exceeds the local rules, your property may be steralized for the construction of any habitable buildings.