In the water
harvesting industry, there is a difference between rainwater and
stormwater. Rainwater is defined as
water from rooftops. When rainwater
reaches the ground, it is called stormwater. Stormwater is typically less clean
than rainwater, as it can contain trash, silt, hydrocarbons, road salt,
nitrates, fertilizers, and other types of contaminants. To understand better
how stormwater collection systems
work, it’s important to know their essential components:
Harvesting
A stormwater collection system diverts water from large, diverse areas that can contain a variety of
contaminants. The runoff it pre-filtered and sent to cisterns where it will be
stored temporarily.
Pre-treatment
A stormwater collection system not only
provides storage, but also filters and sanitizes the water for non-potable
applications. The first step in that process is pre-treating or filtering
runoff before it enters the cistern. Pre-filtrations captures hydrocarbons, debris,
pollutants, and sediments, which keeps the cistern cleaner and reduces the load
on downstream processing equipment. Pre-filtration treatment processes will
vary depending on the source of the water
and how it will be reused.
Storage system
Typical stormwater
management utilizes a detention system
that only holds the water temporarily. Stormmwater
harvesting systems send water to a cistern where it can be retained and used. Some examples of storage systems includeunderground
fiberglass tanks and concrete vaults.
Treatment
