Which condition allows slopes greater than 30 percent to be reclassified as PROVISIONALLY SUITABLE?

• A. If an investigation indicates a modified system may be installed per Rule .1956
• B. If the slope becomes less than 15%
• C. If the soil group changes to Group II
• D. If the site is urbanized

Answer: (A)

When slopes exceed 30 percent, a site is typically not suitable for a standard septic installation. The way to reclassify such a steep site as provisionally suitable is to have an investigation show that a modified system can be installed under the provisions of Rule .1956. This rule provides a pathway to adapt the design to challenging conditions, allowing a higher slope to be considered provisionally suitable based on engineering evaluation and the specific modified system proposed. That is why the option describing an investigation indicating a modified system may be installed per Rule .1956 is the correct one.

The other scenarios don’t establish that provisional suitability. A reduction in slope to below 15 percent, a change to a different soil group, or urbanization of the site alone does not authorize the use of a modified system under Rule .1956 to reclassify a steeper slope as provisionally suitable.