Caring for the Catchment : What you can do

Information for Landscape Garderning and Garden Maintenance.
This information is for owners, managers, and staff of landscape gardening and general maintenance businesses to comply with their general environmental duty by preventing pollutants generated by their activities from entering the stormwater system.

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Benefits for you and your business

• Minimising the risk of environmental fines and prosecutions
• Improving the public image of your business
• Long-term cost savings through increased efficiency and reduced costs
• Improved environmental conditions for all employees

What is stormwater?

Stormwater is rainwater that flows across outside surfaces into stormwater drains and gutters in the street. The water that enters the stormwater drains is not treated and flows directly into our creeks, rivers, and oceans. Stormwater should only contain clean rainwater and no pollutants, such as general rubbish, lawn clippings, fertilisers, irrigation water, sediment or dust.

Why is stormwater pollution an issue?

Landscapers carry out many activities, which can potentially pollute stormwater. The first step is to always ensure that stormwater does not get contaminated. You need to think about all your work practices and ensure that none lead to contamination of water that will run into the street and stormwater drains. You need to think about your outdoor activities - when it rains, will water run off the site, will this water be polluted.

How can I prevent polluting our creeks and rivers?

Water discharged to sewer is treated by SA Water, however restrictions on the types of wastewater discharged still apply. Many liquid wastes cannot go down the sewer, as they will interfere with the delicate biological processes used by SA Water to treat wastewater. Businesses and industry disposing of wastewater must have a SA Water Trade Waste Permit. Pre-treatment facilities may also be required to modify the wastewater before it is discharged to sewer.

Any discharges to the sewer must be in accordance with the requirements of the SA Water Trade Waste Department. Contact (08) 8207 1350 Facsimile (08) 8207 1361.

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What should you know about environmental laws in South Australia?

A number of laws, regulations, policies and guidelines help protect the environment in South Australia and give guidance to business and the general community.

Make sure you know your environmental responsibilities and legal requirements for water and environmental pollution in general.

Under the Environment Protection Act 1993 and Local Government Act 1999 you can be issued with an on the spot fine of $315 if you allow anything other than clean water to go down the stormwater drain.

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How the Landscape Gardener can prevent stormwater pollution

In Transit -
Transporting equipment to different sites usually requires the use of an open tray utility or truck. Loose items such as waste packaging, sand etc, should be covered by a tarpaulin to prevent polluting the roadway. Any wastewater from wash down or brick cutting should be dried or contained in some way before driving so that it cannot spill onto the road and pollute stormwater.

Irrigation -
South Australia is the driest state in the driest inhabited continent on earth therefore water is very precious. As part of the horticultural industry, you have a role in educating the public and encouraging the planting of more water efficient gardens. Understandably, even the hardiest gardens need watering in summer, so consider these basic guidelines.

• Make sure irrigation is set up so as to minimise wastage. Recommend more efficient dripper systems and optimal times of the day for watering. Suggest rainwater tanks for garden watering purposes and consider including tank installation in your service menu.
• Prevent sprinklers from discharging straight into the gutter. Adelaide mains water contains high levels of chlorine. Chlorine can have a sterilising effect on creeks and rivers, killing tiny organisms which help to keep rivers clean naturally.
• Over watering can lead to excess runoff into stormwater. This runoff may transport sediments giving the water a muddy or cloudy appearance. In rivers, cloudy water can cause reduced light conditions and stop important aquatic plants from growing.
• Encourage the revegetation of any bare ground as soon as possible to prevent sediment-laden runoff from these areas.

For further information on water use and irrigation, see ‘Nursery Industry Water Management: Best Practice Guidelines, Australia 1997’, published by Nursery Industry Association of Australia. This publication is available from Nursery and Garden Industry of SA, Ph 84459779.

Green Waste -
Despite the term ‘Green Waste’, leaves, grass, tree limbs, etc, are not good for our waterways. As green waste breaks down and rots, it increases nutrient levels in the water, leading to imbalances and resultant outbreaks of problem toxic algae. The rotting process can also greatly reduce levels of dissolved oxygen in the water hence killing fish and other water organisms.
· Make sure green waste dropped or blown by the wind into gutters or driveways are swept or vacuumed up to prevent stormwater pollution.

Mowing -
Motorised lawn mowers contribute to noise and air pollution. They also burn fossil fuels, a precious resource that should be conserved where possible. Make sure YOUR mower has minimum impact on the environment.

• Always refuel your mower in an area where spills cannot be carried into stormwater by rainwater or irrigation. Make sure you have a spill response procedure and spill kit ready in case of a fuel spill.
• Ensure fuel is stored in an area where any leaks can be easily contained.

Fertilising -
While fertilisers can provide some excellent nutrients for our soils and garden plants, excessive nutrients in rivers can cause outbreaks of toxic algae as well as reducing oxygen levels in water.

• Stop fertilizers from entering the stormwater system by preventing irrigation runoff and stormwater runoff. Use temporary booms or bunding to soak up runoff before it reaches street gutters.
• Beware of weather conditions. High winds can carry fertilizer off site with the potential to pollute stormwater. Develop a spill response procedure and have your spills kit handy in case of accidental spills of liquid fertiliser or pesticide onto sealed surfaces.
• Make sure chemicals are stored in a contained area.

Pesticides -
Pesticides are potentially one of the most damaging pollutants in our waterways as they have the potential to kill delicate native plants and organisms. Without some of these plants and animals in rivers, the waterway cannot support other life such as fish and frogs. They can literally kill the system.

Apart from the active toxic component, pesticides usually contain a surfactant (wetting agent) to assist in the spreading of the toxin which can be just as damaging to the natural system as the toxin itself. Pesticides may be introduced to the aquatic environment through spillage, accidental discharge, or by direct use near aquatic environments. Remember, stormwater drains should be considered as part of the natural aquatic environment. Best practice pesticide management guidelines should be adhered to at all times.

For example:

• Reserve use of herbicides for when is absolutely necessary. If job is small consider physical weed removal.
• Do not use during periods of rain. Plants generally need 24 hours to effectively absorb the herbicide through leaves. Rain occurring during this absorbance phase may be washed off and enter the stormwater system.
• Do not spray during windy conditions as wind may transport herbicide to non-target species and stormwater systems, wanding, cutting and injection methods are preferable. For deciduous trees, inject the herbicide just after leaf drop to prevent the possibility of herbicide transport into waterways through leaf litter.
• Avoid spraying within and around watercourses (including stormwater drains). Consult the Environment Protection Authority on 8204 2000 if spraying in these areas is absolutely necessary.
• Storage of pesticides and accidental spill contingency plans should be as for hazardous goods. Unwanted chemicals must be disposed of at a licensed liquid waste facility. Empty chemical containers should be triple rinsed and punctured before disposal. Look into recycling options for containers.
• Train all staff in the correct use of pesticide and their potential impacts on the stormwater system.

Building -
Landscape gardeners may perform all manner of building activities in daily operations, with retaining walls and paving being the most common structures built.

Paving -
Brick and paver cutting has a huge potential to pollute stormwater with dirty wastewater flowing along sealed surfaces into gutters. All wastewater and dust from cutting must be prevented from entering the stormwater system. Do not perform brick cutting on the road or footpath.
· Consider purchasing a ‘BRIKASAURUS’, (a brick cutter, which recycles water and captures all dust pollutants), or invest in a Spill Safe mat to hold all wastewater and pump it into a drum for proper disposal.
· Alternatively perform all cutting on an appropriate vegetated area where wastewater cannot reach the stormwater and use a hessian bag attached to your cutter to filter the wastewater.

Concreting -
All residues and wastes from concrete works should be prevented from entering the stormwater system.
· On site mechanical or manual concrete mixing must take place in a designated area capable of containing all excess water, residues and waste.
· If site conditions require the use of concrete pumps from roadways, temporary booms or bunds need to be provided across all down-slope gutters to contain any spillage. Spilt slurry must be removed from the road before the bunds are removed.

Carpentry -
When cutting wood, collect and dispose of sawdust so that it cannot pollute the stormwater system.

Excavation -
Try to prevent drag out of sediments by machinery off site and into gutters. Sweep out or vacuum surrounding street gutters at the end of the day to prevent stormwater pollution from overnight rains.

If it is necessary to leave stockpiles of fill on a site, construct a silt fence around the base of the stockpile. A silt fence is a temporary sediment control measure made from woven fencing mesh and filter fabric. Silt fences are quick and easy to install and can be moved from site to site. Always give piles of fill a light spray of water before leaving them for the day. This makes a crust to form over the top, reducing the likelihood of wind erosion.

If using moss rocks make sure your supplier has not removed them from riverbanks, as this can cause serious erosion up stream.

Equipment Wash Down -
Wash vehicles and equipment on an appropriate vegetated area or in an approved wash bay. Do NOT wash vehicles in the street or driveway.
Wash bays are generally connected to sewer or occasionally to an underground tank, which is pumped out by a licensed liquid waste contractor. If you wish to install your own wash bay, ask your local council for approval. Well-designed wash bays should be enclosed on three sides to prevent splash contamination of their surrounds, with a speed hump at the entrance to prevent water from escaping. The wash bay should be roofed to prevent entry of rain, and the floor paved with concrete.

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For information

Please contact the stormwater pollution prevention officer at your local council, SA Water Trade Wastes Section (phone 8207 1350), the Environment Protection Authority (phone 8204 2000) or your Catchment Water Management Board.

The above information is offered in good faith. It is not legally binding in any way and should not be taken as a statement of law.