ROOFTOP RUNOFF COLLECTION FOR GROUNDWATER RECHARGE OR REUSE

The objective of this project is to divert rooftop runoff that is being lost as surface runoff into a system that will allow for future use. This system will consist of a storage tank used to store the rainwater with an overflow into a drywell, or a drywell that can recharge all roof runoff directly into the groundwater supply. A variety of drywell systems have been evaluated to develop feasible alternatives. Evaluations of these alternatives were based on cost/benefit analysis, efficiency, and regulatory requirements.The project is intended to address water supply issues that Franklin, Massachusetts is currently facing as a result of increased development. The town currently has 70% of its residents on sewer. Residential wastewater is sent for treatment and then disposed of into the Charles River. By implementing this technology, the amount of clean water introduced into the groundwater is expected to increase while also allowing for stored, non-potable water uses such as lawn watering.Drywells are cost effective and easily implemented in most situations. The dimensions of each system will be site-specific due to constraints such as soil conditions, size of the property, size of the roof, and the seasonal high depth to the groundwater table. It is expected that the results of this project can be used as a resource for Franklin in developing site-specific roof runoff collection systems as part of their water resource management plan.