What the grinding leaves outside the room.

Where the water may not go

The oldest of the rules is South Australia’s. EPA South Australia’s guide for concrete cutters, a 2003 publication (EPA 495/03), records that from 1 October 2003 the state’s Water Quality Policy of that year prohibited pollution of the stormwater system and of its rivers, creeks, ground and marine waters. The policy’s clause 17(1) stated the duty: a pollutant on the Schedule 4 Part 1 list may not be put into any waters, nor onto land from which it could reach them. For concrete cutters, the Schedule 4 Part 1 list of pollutants takes in brick, bitumen, concrete cutting wastewater and concrete waste. And the page’s line for the end of a job is simple: no sediment may be left in the gutter or the drains.

What the page offers instead

The same page does not stop at the prohibition; it lists what a cutter can do instead. One option is to dig a hole, tip the slurry in, and let the water evaporate or soak away. Another is a baffle or a boom, set to keep slurry and wastewater out of the stormwater drains. And a third is to pump the water into a container, which opens the disposal options: an evaporation or soakage pit, a garden, or the sewer. The last of those carries a condition: discharging to the sewer needs a trade waste permit from SA Water, the page notes.

The duty under the site

The state’s building-sites handbook, in its 2004 second edition, gives the duty underneath all of that. Its rule is a general duty: where an activity pollutes the environment, or might pollute it, it may not proceed unless every reasonable and practicable measure has been taken to prevent or minimise the harm. Its introduction says that everyone on site is responsible. For concrete works, it says all residues and wastes the work produces must be kept out of the stormwater system. Waste slurry is to be left to dry, then either dealt with on site or carried to a waste depot that is licensed.

The two jobs Victoria names

EPA Victoria’s construction and demolition guide, in its edition of September 2025, keeps a chapter for activities that produce wastewater. Under a heading that reads Other activities resulting in wastewater, it names two that belong to a concrete job. The first is concrete pour works, where the control is to seal the concrete once it has cured, so that run-off water does not turn alkaline. The second is high pressure washing of concrete slabs, where wash water carrying concrete residue must be kept out of the stormwater system. And it tells the people it is written for, in civil construction, building and demolition, that understanding and assessing their risks is their own responsibility.

New South Wales: collect, store, treat

NSW Environment Protection Authority’s guidance for concrete wastes, which the authority flags as possibly out of date and last updated on 14 July 2021, is written for developments, and it starts at the collection point. Whatever the size of the development, it says, the developer has to make sure the wastes from concrete are effectively collected, stored and treated. The treatment has a standard to meet: the facility for it has to be designed to correct the pH and remove non-filtrable residues, to the standard the local sewerage authority sets. And the pit for the waste has to be lined with a vapour membrane, so that the concrete cannot get into the ground.

The hours, state by state

A grinder is also a noise, and noise has a timetable. The three states below write it differently, and each row stands with its own agency and its own date.

• New South Wales NSW Environment Protection Authority, page updated 31 August 2026

  The state’s noise control regulation sets times at which noise from domestic activities ought not to be heard in a residential room next door. The page’s table carries a row for power tools and equipment, its own list taking in powered garden tools, electric or pneumatic tools, circular saws, chainsaws and gas or air compressors. That row’s prohibited hours: on weekends and public holidays, before 8 am and after 8 pm, and on any other day, before 7 am and after 8 pm.

• Victoria EPA Victoria, page updated 23 May 2025

  The residential noise page gathers its items into a table under Regulation 114 of the Environment Protection Regulations 2021. The group the table calls group 2 covers, among its items, gas or air compressors, and pneumatic power tools, hammers or other impacting tools, and grinding equipment. For that group, the table sets prohibited times on weekdays as well as on weekends; on weekends and public holidays they are before 9 am and after 8 pm. The page also defines its own subject: residential noise includes repairs and maintenance on a building that already exists, and it leaves out the noise of building, demolishing or removing a home.

• South Australia EPA South Australia, information sheet updated September 2023

  The construction noise sheet covers only work on a site that needs development authorisation under South Australia’s Planning, Development and Infrastructure Act 2016. For those sites it sets the window: construction noise that harms amenity is permitted only between 7 am and 7 pm, and only from Monday to Saturday. Near homes, that is when ordinary construction activity on such a site is allowed, power tools and machinery among it. And the sheet’s advice for the noisy parts goes further: every reasonable and practicable measure has to be taken to cut the noise and its impact, including holding back the noisiest work, masonry saws and jackhammers among it, until after 9 am.

What the three states give together

Read together, the three states make different things of the same machine. South Australia writes the water into its water quality policy and then lists the ways to keep it out; Victoria names the two concrete jobs in its wastewater chapter, with one control for each; New South Wales puts the duty on collection, treatment and a lined pit. On the noise, the three agree only that there is a timetable, and each state’s hours stand on their own.

One thing is worth stating plainly: every rule above is the agency’s own, set out where the work is regulated, and nothing here is a set of steps for doing the work.

Where this goes next

The machine itself, and what three state regulators say about its wet and dry methods, is in the grinding guide. The dust it raises, and the numbers the air is held to, is in the dust guide, and the surface the pass leaves behind is in the finishes guide.

This guide is general information from the environmental agencies named with each rule; it is not legal advice for any site.