Under what condition are two-way clean outs not required on building storm drains?

Two-way cleanouts are critical components in drainage systems that allow for maintenance and cleaning of the pipes. They provide access points for clearing blockages and performing inspections, ensuring that the system operates efficiently.

The condition under which two-way cleanouts are not required is when the storm drain drains to daylight and the distance from the building is 100 feet or less. If a storm drain discharges directly to an open area (or daylight) within this distance, the likelihood of blockages occurring is significantly reduced, as there is less length of pipe where debris or sediment can accumulate. Additionally, the proximity to daylight allows for easier observation of the drainage performance, which diminishes the necessity for maintenance access points like two-way cleanouts.

In contrast, regular maintenance access, the type of material used for the drain, or specific filtration systems do not inherently justify the absence of two-way cleanouts. Regular maintenance access might aid in reducing blockages but does not negate the code requirements, while the type of pipe material or filters may have different implications regarding durability or functionality but do not address the structural and access needs of the storm drain system.