New property developments must comply with local council requirements with stormwater management and drainage.
Stormwater is water that comes from rainfall during a storm or regular rain periods. Once the rain hits the ground area, it will typically soak into the soil, remain stagnant on a hard surface such as a road, path or other hard surface.
Large amounts of stormwater will run off into drains, creeks, rivers and waterways. In a developed residential or commercial area, stormwater that is not managed can cause issues of flooding properties or contamination in waterways.
Stormwater management is the process of reducing runoff of rainfall into streets, properties and other sites.
Typically, when rainwater hits the ground, it’s absorbed into the soil and replenishes the ground and plants, trees. When the rainfall is heavy, it can create an excess of water that flows into drains, roads, property areas and may cause flooding. This water may also then carry debris, garbage that contaminates the waterways and oceans.
Structural stormwater treatment systems are created to support water sensitive urban areas to meet local council requirements.
Areas that were once naturally vegetated and now have homes, roads, carparks and fields can have an impact on how water flows in the event of a storm. This includes:
Contaminants that flow with this water can cause significant issues if it enters waterways and oceans.
A stormwater system helps treat and filter pollutants from the water before it reaches ecosystems.
As mentioned above, protecting the ecosystem and human health is the top priority in stormwater management systems.
Increasing populated urban areas can cause the water to be contaminated by pollutants which can cause irreversible damage to the local ecosystem.
Types of stormwater pollutants include:
Suspended solids usually originate from:
These pollutants can be closely associated with other pollutants, such as nutrients, heavy metals and hydrocarbons. They can also be divided into two categories; suspended solids and dissolved solids.
Suspended solids are particles larger than 0.45 μm in the water while dissolved solids are smaller than 0.45 μm.
Nutrients are chemical compounds such as nitrogen, phosphorus, calcium, carbon, iron, manganese and potassium. From the perspective of water quality, nitrogen and phosphorus compounds play the most critical role in environmental degradation.
While nutrient compounds are essential for plant growth, excessive amounts in waterways can cause cascading damage to all forms of aquatic life.
Richness of nutrients in a body of water can promote the excessive growth of plants which in turn threaten the health of aquatic habitats. Excess plant life in water systems can reduce light penetration through the water and block the ability of some organisms to synthesise the nutrients they need from sunlight.
Excess plant growth can also decrease the amount of oxygen in the water thereby killing other organisms living in and depending on the aquatic environment.
Organic carbon originates from many sources directly and indirectly. Plant litter and soil erosion are two direct sources of organic carbon. Indirect sources include decaying vegetation, atmospheric deposition, waste materials and effluent (such as septic tank leaks, animal and bird faeces and spillage from vehicles transporting organic materials).
Biodegradation and chemical oxidation are the processes through which organic carbon is broken down and consumes oxygen. When organic carbon is mobilised by stormwater, it can lead to the depletion of dissolved oxygen in water systems and habitats, leading to the death of fish and other aquatic life which rely on oxygen for their respiration.
Due to their high levels of toxicity and potential of causing harmful effects, heavy metals are considered a critical pollutant. Not only are they a concern to human health, they also are concerning contaminants affecting our waterways and ecosystems.
Heavy metals include:
Exposure to these heavy metals can affect red blood cells, the nervous system and many organs very negatively. They can also be contributing causes of certain types of cancer, metabolic poisoning and damage to kidneys among other body systems.
As heavy metals can easily bioaccumulate in humans, plants and animals, they are a big threat to health and must be filtered out of the waterways.
Hydrocarbon compounds include oils, phenols and grease originating from natural, environmental and anthropogenic pollution. Human activity, especially commercial or industrial activity, commonly results in hydrocarbons and pollutants leading to emissions of sulphur dioxide.
Stormwater runoff from road surfaces has been reported to contain a greater hydrocarbon load than water from rooftops. Due to the heightened risk and ability to affect ecosystem health, hydrocarbons are a major concern in relation to stormwater runoff and must be filtered out.
Acidity and Alkalinity
Water quality can be determined by the status of a number of factors. The acidity and alkalinity of the water are reliable indicators. Water with moderate amounts of acidity or alkalinity is fine for consumption without adverse effects.
High levels of acidity or alkalinity in water can indicate chemical pollutants are present and that the water is a risk to aquatic habitats and also the human body. Acidity and alkalinity of water can be determined by measuring the pH level.
If you require more information on stormwater management, contact us today.