The perc test is the site and soil evaluation that determines whether a site is suitable for installing a septic system and most often what type of system installation is suitable for a particular site.

The septic system design is the set of plans and specifications detailing the installation requirements of the system. The design takes into account the site and soil conditions present on a property to assure that the system installed complies with applicable regulations and is environmentally safe and sound to operate.

In Virginia, only LOSE's (Licensed on site soil evaluators) or PE's (Professional engineers) are allowed to design septic systems. AOSE's (aternative LOSE) and PE's can design alternative systems that comply with applicable laws and regulations.

Often the same people who evaluate your lot can design your septic system. This is true for conventional systems and most simple alternative type systems. There are cases when the design required is beyond the scope of the LOSE/AOSE, by practice or as defined by law. There are also sites with very limiting conditions that often require the services of an experienced CPSS/AOSE (for evaluation and consultation) and a PE (for design) to formulate a suitable system configuration.

Again, I think Soil and Environmental Technology is the place to start. Especially, if you have been told by someone else you need an alternative system design. I know it's hard to pay for what you think is the same service twice, but until we've evaluated your lot, you haven't got your moneys worth. Call for references and a free in office review of your evaluation.

The EPA has an excellent homeowners guide explaining the basics. www.epa.gov/owm/septic/pubs/homeowner_guide_long.pdf

You should call a licensed installer for a quote if you already have your plans.

The installation cost of a septic system can vary widely depending on the site and soil conditions, the installer, and the type of drainfield that is installed. These ranges are only a guide for you to compare relative costs of the different types of systems commonly installed.

On average you can expect to pay $4,000-$6,000 for a conventional septic system, $6,500-$8,500 for a conventional septic system that requires a pump, $10,000-$15,000 for an alternative septic system that requires pretreatment into conventional drainfield lines, and $20,000-$24,000 for an alternative septic system that requires pretreatment into drip irrigation.

Contact SETEC (540 381-0309) for recommended installers.

Design and inspection services are billed at an hourly rate of $75/hr. Most often its about $450-$600.

Anything other than a conventional septic tank and drainfield system. Most often they involve some kind of aerobic sewage treatment in addition to a septic tank. Site and soil conditions usually dictate whether an alternative type system is required.

Not really. Alternative type systems substitute a constructed treatment process for natural sewage treatment processes that normally occur in the soil. It's only where the soil resource is inadequate that alternatives need to be utilized. A properly designed and constructed conventional system sited on soils with an adequate treatment capacity is about as "green" as it gets. All sites aren't suitable for conventional systems, though.