DESIGNED BY BLUE SKY CONSULTING Why test? The purpose of testing is to identify an area (or areas) on a property suitable for a septic system. Test results serve to characterize soil and site conditions in order that a system appropriate for the property can be properly designed and installed. For vacant property, a building permit usually will not be issued without an approved septic system design. In most cases, testing will determine whether or not a property is “buildable”. How large an area needs to be tested? This depends upon soil conditions, the volume of wastewater produced (estimated by the number of bedrooms for a residential site, or the type of use for a non-residential site), and the type of system. Generally speaking, a conventional, trench-type septic system for a 3- to 4-bedroom residence on a property with “average” soil conditions will require an area about 3000 to 5000 square feet in size. An approved alternative system such as a mound type, buried sand filter, or drip irrigation typically can be constructed in smaller areas. How many samples are needed? Requirements vary by county or municipality, but typically 3 to 4 samples are obtained and examined for each area proposed for the septic system. Additional sampling may be required if the soil conditions are extremely variable or if the system area is unusually large as a result of large wastewater volume or poor soil or site conditions.