*Concrete sump pretreatment device. [https://acfenvironmental.com/products/stormwater-management/filtration/rain-guardian/ Rain Guardian] is one example of a proprietary sump device. | *Concrete sump pretreatment device. [https://acfenvironmental.com/products/stormwater-management/filtration/rain-guardian/ Rain Guardian] is one example of a proprietary sump device. |