Crowns of both Wisconsin mound and area fill systems must have at least what percentage of fall to avoid water ponding?

Having a minimum fall of 1% at the crowns of both Wisconsin mound and area fill systems is essential to ensure proper drainage and prevent water ponding. This slope facilitates the movement of water away from the system, promoting effective absorption into the surrounding soil. When there is insufficient slope, water can accumulate on the surface, leading to saturation of the soil, which may impair the system's functionality, cause unpleasant odors, or even result in system failure.

A fall of 1% strikes a balance that provides enough gradient to encourage drainage while being achievable in construction. This characteristic is particularly important in maintaining the long-term efficacy of soil absorption systems, making it a critical standard in proper installation practices.