There are new laws - "Emergency Laws" - in effect now in the state of Virginia which regulate the maintenance and legal operation of so called "alternative septic systems".
Alternative septic systems are anything that are not "conventional" systems. Some common types include: Advantex, Delta Whitewater, Puraflo, Eco-flow and Sandfilter. If you have one of these types of system (available only for the past 20 years), then these laws DO apply to you.
Under these new regulations, HOMEOWNERS:
Must maintain an Operations and Maintenance Manual.
Must maintain a relationship with a licensed operator. In most cases this means that you have to have a service contract, unless you are or you directly employ a licensed operator.
Assure that the licensed operator visits, collects samples and makes adjustments as needed for proper maintenance of system and to be in compliance with the regulations.
Make these records available to anyone who purchases the property.
In addition, if you have an "alternative" system in Loudoun County, you are required to have have an annual "1067" inspection. The inspector must be approved by Loudoun County to conduct such an inspection (see link below of approved inspectors).
The costs of a maintenance contract and the various inspections vary depending on your system, but shouldn't be more than a few hundred dollars a year. In most cases it will still be less expensive than paying a public utility for sewage services.
A note about contractors:
Please note that all contractors are not equal. In Virginia, there are separate licenses issued for installers and operators. Although one may carry both licenses, not all do. Further, Loudoun has specifically provided a list of approved inspectors to be in compliance with their law... approved inspectors may or may not also be licensed operators or installers. Personally, I suggest one stop shopping... hire someone that is a licensed 1067 inspector, a licensed operator and even a licensed installer, in case you need a new tank or drainage lines. In my opinion, this will usually offer more seamless service and overall better maintenance. Companies that can offer you all relevant services may even offer you discounts on larger repairs that fall outside of the normal maintenance realm. On local company that offers this "one stop shopping" with licensed operators and installers and are approved to conduct 1067 inspections for Loudoun, is http://www.ses-company.com/.