Our use of water – impacts on water quality

Find out how some of our daily interactions can impact our local waterways.

We use water every day. We also use goods and services that rely on water. Find out how each of these can have an impact on water quality and what we can do to lessen the impacts. The interactive Land use – impacts on waterways has additional information.

To use this interactive, move your mouse or finger over any of the labelled boxes and click to obtain more information.

Background image of sprinkler, Mariusz Blach, 123RF Ltd.

Transcript

Drinking water

Clean drinking water is essential to our health. All water in the Waikato region has to be treated before it can be used for municipal supply.

In Hamilton, water is taken from the Waikato River. Hamilton City Council reports that its water treatment plant produces over 20 million glasses of high-quality drinking water each day! However, only a small portion of that is used for drinking. The rest is used for showers, in the garden or for industrial and other purposes.

Hamilton city has a limit to the amount of water that can be drawn from the Waikato River each day. The water requires several stages of treatment before it can be used safely. This treatment process is costly, and the more treatment required, the greater the cost. Conserving water is good for the environment and it saves money too!

In rural areas, drinking water comes from rainwater collection tanks and from aquifers. Individual homeowners are usually responsible for their own drinking water quality.

Acknowledgement: Public domain

Wastewater

All household wastewater from pipes connected to urban homes, businesses and schools goes to a wastewater treatment plant. (A small percentage of people have composting toilets and alternative greywater systems.)

Once we have used water, it must be treated before being returned to the environment. Like water treatment for supply, this process has a cost, and the more water we use in our houses, schools and businesses, the more water there is to treat.

In rural areas, household wastewater is treated in wastewater treatment systems and septic tanks and disposal fields in the soil.

Wastewater must be treated to reduce bacteria, nutrients such as phosphate in faeces and detergents and nitrogen in urine. Nutrients increase the growth of plants in waterways, and this can lead to eutrophication.

There are a number of conservation measures that we can take in our schools, businesses and homes to help reduce the amount of wastewater.

Select here to view the video transcript and copyright information.

Acknowledgement: The University of Waikato Te Whare Wānanga o Waikato and Waikato Regional Council

Stormwater

Stormwater drains are designed to drain water away from buildings and sealed surfaces such as roads into natural waterways. This water is not treated, and any chemicals, sediment, oil, detergents, litter and animal faeces that are on the surface can be washed down into the waterway. Each of these can have impacts on the quality of water.

Paint, leftover chemicals, oil and other poisonous substances should be returned to the place they were purchased from or disposed of safely at a waste transfer station. They should never be emptied down the drain. Vehicles should be washed on the grass rather than the road or the driveway, as grass helps to filter detergents and reduce the amount entering waterways.

Acknowledgement: V. Nikolaienko, 123RF Ltd

Industrial

As consumers, we rely on industries for lots of our goods and services. Industries use water in many different ways:

• to process food, meat and dairy products
• to process pulp and paper
• to manufacture items
• in professional cleaning services
• in chemical and concrete production
• in mining and quarrying.

Industries may require resource consent and have regulations about the amount of water they can take and how wastewater is processed.

Regional, district and local councils monitor waterways and can prosecute businesses who do not meet their obligations under the Resource Management Act.

Acknowledgement: Public domain

Primary production

Primary production includes forestry, horticulture, viticulture and poultry, sheep, meat and dairy farming. Primary production is important to the New Zealand economy.

It is also important to all of us as individuals. Most of us rely on supermarkets for our food and drink and other businesses for paper, timber, furniture and more.

The Waikato region’s topography, soils and climate are well suited for farming. Stats NZ reports there are approximately 1.9 million dairy cows in the Waikato region. The region also has thousands of hectares of maize, fruit and vegetable production and plantation forestry.

Primary production can have impacts on water quality. Often they are cumulative effects and not caused by any one land user or property, but added together, they can have significant impacts.

Primary producers have to follow regulations about the amount of water taken and discharge of wastewater and effluent. Many producers go beyond what is required to minimise their effects on water quality.

Regional councils are able to prosecute producers who breach their resource consents.

Acknowledgement: Image licensed through 123RF Ltd

Electricity generation

Water is used in the generation of electricity – through hydro power, geothermal power or burning coal or gas at Huntly Power Station, where water is used as a coolant. Each type of electricity generation potentially affects the Waikato River.

Companies that use water in the generation of electricity have to comply with the conditions set out by resource consents. For example, consents cover the amount of water taken and the temperature of water discharged back into the river.

Hydro power development disrupts river systems and blocks the migration of eels and fish, which need to travel up and down to complete their life cycle. Fish-friendly culverts, dam bypasses and other technologies are used to help native species migrate.

Acknowledgement: Michael Hind

Recreational uses

Humans enjoy living beside and having access to water for swimming, fishing, boating and other water sports. However, we need to take care so these activities don’t impact on water quality. Litter, boat fuel pollution and the introduction of exotic plants and animals have contributed to the slowly decreasing number of places that we can safely enjoy these activities.

Ensuring that boats are well maintained, litter is disposed of appropriately and plants and animals are not transferred on propellers between waterways are some of the ways that we can protect water quality.

Acknowledgement: Biosecurity NZ

Pedagogical hints

Water quality is a complex issue. We all use water and goods grown or manufactured with water, so water quality is a responsibility that we all share.

At times, there can be an urban-rural split when it comes to water quality issues. Diffuse pollution is a major cause of water pollution. It can come from land use and underperforming wastewater and stormwater systems in urban areas and from intensified farming/horticulture in rural areas.

The following resources may be useful when managing discussions about water quality.

• The article Teaching ethics collates Hub resources that can be helpful when dealing with difficult issues. It includes the Ethics thinking toolkit and the Ethics in science planner.
• Concept cartoons can be used to show a range of viewpoints to engage students and stimulate discussions.

These Rivers and Us resources are in a downloadable PDF format.

• Water use amounts
• The stormwater problem
• What happens to the water used to wash a car?
• Discussion cube prompts

Acknowledgement: Polluted water illustration by Gabriel Jose, 123RF Ltd. Copyright The University of Waikato Te Whare Wānanga o Waikato