When sizing our tanks, we don’t specifically include a buffer volume like you would with a wastewater tank for accommodating extra visitors. It’s a different process. Our engineers take various factors into account. They calculate the current runoff rate from the site, the amount of non-absorbable runoff, and consider the downstream system. They also consider Climate Change by applying a safety factor of around 30-50% to account for anticipated increased rainfall.
The tanks are designed to handle rare storm events, such as one in 30 or one in 50-year storms, and accommodate the projected changes in weather patterns. So while there may be some additional volume in the tank, it’s not a buffer in the traditional sense. Our goal is to match the tank size as closely as possible to the drainage plan we receive, considering all these factors beforehand.
