First Flush Diverters for Rainwater Harvesting
Rainwater harvesting can only be of benefit to people if the water that is collected is clean and safe for human consumption. An efficient and convenient manner by which it is done is the use of a first flush diverter. It is a method by which the dust, debris, airborne contaminants and bird or animal droppings from first flush rainwater is reduced or eliminated. The rainwater that is harvested from rooftops in dry remote or urban settings is particularly susceptible to being adulterated or contaminated. A first flush diverter can be used in a variety of ways, such as an overflow type, float valve type, flow rate type and electronic conductivity type. At present, the method of controlling the quality of water in roof water collection systems is curtailed to the divergence of first flush rain as well as the infrequent cleaning of various cisterns.
Size and Mechanism of First Flush Diverters
First flush diverters range from 90mm to 150mm in size and are installed alongside a downpipe that is used to supply water to the storage tank. It makes use of a ball and seat system, which is a simplistic automated system not dependent on manual intervention nor any mechanical parts.
The mechanism of the first flush diverter is that as the water level increases within the diverter chamber, the ball inside starts to float. Once the diverter chamber reaches its maximum capacity, the ball stops floating and starts to rest on a seat that is situated within the diverter chamber. What it does is that it prevents any more water from entering into the diverter and then the consequent flow of water is mechanically redirected alongside the pipe system to enter into the storage tank.
First Flush Devices
Essentially, first flush diverters are involved in the collection and conveyance of water, and more often found in urban areas, as opposed to remote ones. This because people living in rural areas do not have the awareness of these devices and not possess the resources to afford such devices.
Devices used include using sediment traps, which utilize a bucket for tipping that stops debris and dust from the catchment to fall into the tank. The installation of a first flush device is extremely beneficial as it allows the divergence of the first batch of rainwater to move away from the tank. A first flush device cannot be properly utilized without the regular inspection and cleaning of downpipes and gutters, as otherwise the system can get blocked with dirt, dust, and debris. Moreover, such inspections allow any potential leaks to be detected thus allowing more efficient utilization of rainwater for harvesting. Those individuals who use first flush devices have the ability to drink water that is free from contamination, thus making it fit for domestic usage.
Benefits of First Flush Diverters
The benefits of a first flush diverter are that no mechanical parts are used, hence people can easily install and operate them, as no technicalities or expert knowledge is needed.
The maintenance requirements are low; hence women in their homes can inspect and maintain these devices conveniently.
The installation of first flush diverter is extremely easy and quick as it only requires the use of pipe that is joined together with glue. It allows the first flush device to be easily used together with a rain head, thus increasing the capacity of the stored rainwater.
A person using a first flush diverter will witness an improvement in water quality, protection of their water pump and their internal appliances.
Last, but not the least, the largest contribution and advantage of these devices is that they prevent the collection of spiders, mosquito eggs, bird droppings, sediment and debris from infiltrating the rainwater tank. With the rise of diseases such as dengue virus, it is all the more important for people to start investing in first flush devices.
What can be garnered from the aforementioned information is that for those people who make usage of rainwater harvesting systems, they need to install a first flush diverter. Otherwise, with the advent of adulteration of rainwater due to chemicals as well as ‘acid rain’, it is extremely important to ensure that the water being consumed from rain is fit for human drinking and domestic usage.
