Storm water is water that is produced from rain, and possibly melting snow and ice, which flows over solid surfaces, capturing gross pollutants, sedimentation, nutrients, heavy metals and a wide range of other pollutants. The majority of this water infiltrates into the soil, or evaporated or run off and enter nearby waterways. In natural areas, free from construction, buildings, motorways and agriculture etc. the water just soaks and absorbs into the soil or evaporates. In developed areas, not only does the range and concentrations of pollutants grow and grow, but the areas in which the water is usuall absorbed or evaporated is removed, the storm water is funneled through stormwater drainage systems and directly into our rivers, streams and waterways. The natural processes of stormwater removal such as infiltration evaporation and filtering are greatly reduced, causing the concentrations and size of pollutants entering our waterways to drastically increase.
Stormwater treatment and management is about protecting our environment. When we develop stormwater treatment systems we are designing ways in which to protect our environment, and rid our environment and ecosystems of pollution and contamination. Hence the need for these systems is vital for our environment and ecosystems health and prolonged life. From gross pollutant traps which remove larger plastics, debris and sedimentation from our waterways, keeping our oceanic and water ecosystems protected from the well-known dangers of ocean and marine life coming into contact with plastics, to our tertiary treatments to remove heavy metals, organic nutrients and colloidal fine particles from our water systems and prevent from poisoning the environment. If the management of stormwater is conducted properly, with effective and efficient technologies in place, we can improve our water ecosystems and effectively lengthen our environments life.
Not only does proper stormwater treatment and management protect our environment, it also has several other benefits that are less widely known. These management systems can reduce flooding to protect people’s lives and properties, reduce the demand on public stormwater drainage systems, support healthy streams and rivers, and create healthier, more sustainable and viable communities. Effective stormwater management provides not only vital environmental benefits, it also provides social, economic and communal benefits.
It’s important in society to maintain a clear image of the bigger picture. As our society continues to grow in population and city size, we increase the area covered by impervious and non –absorbent surfaces that do not allow infiltration and absorption and in turn increase the amount of polluted runoff. We must continue to implement these stormwater treatment technologies not for just the current benefit, but also for the future and more vital benefits.
Hydrocarbons make up a large majority of the pollutants present in water, being produced from fueling stations, cars and motor vehicles and in industrial processes. If these hydrocarbons flow into the stormwater systems through surface runoff they must be treated efficiently and completely. Large proportions of hydrocarbons and oils in water ways is extremely harmful to the ecosystem life that exists in the water systems that follow our stormwater treatment. There are several efficient processes of hydrocarbon removal:
In reality a combination of these processes is the best process for the removal of hydrocarbons from stormwater. Systems that encapsulate these are the greatest for hydrocarbon removal and management.
When considering what are the best processes for treating stormwater runoff in a certain application, it is vital to consider the various forms of contaminants that are produced in these areas, as well as the environment in which the application is to be placed in. Carparks developments, have the tendency for high levels of oils, gross pollutants from high foot traffic, hydrocarbons and heavy metals produced from cars ad rooftops. These areas need to be thoroughly treated for discharge back into the environment, as usually is the requirement for water treatment in these areas. Hence the tertiary treatment systems are required for these areas, with all of the protector tertiary designed systems removing the required contaminants that are produced from these areas.
The processes best used for carparks as their applications include:
There isn’t one single process that best removes a certain contaminant. To best tackle the removal of pollutants, a wide range of techniques need to be used in conjunction with each other to ensure the most effective removal possible. High traffic areas have a series of pollutants that remain a big issue in treatment of these systems. High traffic areas produce contaminants such as high amounts of hydrocarbons, high levels of gross pollutants, heavy metals and fine sedimentation. Hence solutions are required to remove these pollutants are produce water for the environment with as low percentages as possible. Hence a combination of primary, secondary and tertiary, and depending on the weather conditions and flow rates of the area, retention systems.
The processes which we recommend to be utilised in the removal of pollutants produced from highways include:
The process of physical filtration is the mechanical and physical removal of solids or fluids from a fluid through forcing the flow of the filtered liquid through a medium. This process is most simply described by the use of a medium having perforations smaller than the size of the particles in which are being endeavored to be removed.
Biodegradation is the disintegration of materials through bacteria, fungi or other biological means. Essentially the process of biodegradation is in which material is consumed by microorganisms. This process can be implemented effectively in stormwater treatment, in conjunction with soil. Due to soils high absorbance, water is absorbed into the soil media in which these bacteria and microorganisms live, and the contaminants are slowed in the soil and are hence consumed by the organisms living in the soil. The water flows out of the soil with contaminants removed. These microorganisms in fact use this process to increase their population and remove the contaminants more efficiently. The matter which is able to be consumed by these microorganisms are generally organic materials such as hydrocarbons and nutrients.
Several things are vital in the construction of an effective and efficient stormwater treatment system. Firstly, the system needs to encapsulate all process required for the site in which the runoff is being produced. This means careful considerations of the surrounding environment and its specifications which include:
Once these considerations are reviewed, we can effectively determine which processes need to be used to remove the contaminants that shall be produced. From this it can be decided which systems must be installed, whether it be a single or a complex treatment train. It must be also ensured that no unnecessary systems are implemented which will provide no significant assistance to the stormwater treatment process. If all of the contaminants that can be present are considered, the correct processes can be implemented to ensure effective removal before the water is returned to our waterways and ecosystems.
It is vital that only proven well tested processes are used in the treatment proesses. This means that the process in which are being implemented must all be proven and ensured to be THE MOST effective and efficient in our processes. This is why there is constant need for redevelopment and research into the stormwater treatment technologies so that we are constantly improving the processes in which we currently use.