[video: Auckland Council logo (pōhutukawa flower over water). Music plays. Title ‘Working with concrete’ shows over shot of worker smoothing concrete using a handheld tool.]
[video: Young man in high vis vest and workwear standing in front of area being concreted, with a number of other workers in the background. Caption shows: Sean Brown, Brown & Brown Builders Ltd.]
Sean: On almost every building site, you’ll be working with concrete. It is a terrific material for building, but it can be very toxic for the environment. So here are some guidelines for how to work with concrete.
[video: Dirty, muddy water running down a building site with digger or similar vehicle at top of site.]
Sean: Firstly, never put concrete or wash concrete down stormwater drains.
[video: Wet-looking concrete around a drain.]
Sean: Concrete and cement are extremely toxic because they have a high lime content with a pH of 12 out of 14.
[video: Dirty looking creek. Sean kneeling in front of rows of dead fish of different sizes laid on the grass. Mound of dead eels.]
Sean: This can easily kill fish, eels and other wildlife.
[video: Sean holding small plastic bottle with liquid inside it.]
Sean: Just this much concrete – about 1L – takes 5 truckloads of water to dilute.
[video: Five duplicate images of ‘Hibiscus Water’ tankers.]
Sean: 100,000L of water to dilute 1L of concrete!
[video: Building site with mud and muddy water. Constructed hole in the ground filled with water. Debris and dirty water at the edge of a drain.]
Sean: So what you want to do is keep excess water, like rain or washdown water, away from the concrete, because it will go down the stormwater drain and cause pollution.
[video: Sean standing in front of a concrete truck, lots of blue sky in background.]
Sean: It’s very important to never schedule your concrete pour for a rainy day. Pick a day like this. It’s better for the job, and for the environment.
[video: Building site prepared for concrete pouring, a little water in the prepared area. Closeup of water in a prepared hole.]
Sean: If you’re going to do a concrete pour after it’s been raining, make sure you remove water from pile holes, footings and foundations before pumping concrete.
[video: Dirty water spilling down a section and onto the footpath. Creek filled with dirty water.]
Sean: That way, concrete-laden water won’t spill over and go down the drains. Because that can have a really bad result.
[video: Rear of concrete mixer truck with wheelbarrow below it, over unsealed building site surface.]
Sean: Ensure delivery and pumping is kept on site on an unsealed surface and away from stormwater drains and trees.
[video: The concrete truck with large mat underneath it.]
Sean: If pumping occurs on the street, make sure you use large bins or mats under the pump hose to collect spills.
[video: Watery material being poured from the truck into a wheelbarrow. Worker tips it into what looks like a dedicated area on the unsealed surface. Wheelbarrow being hosed off in same area.]
Sean: Divert or contain any excess slurry or wastewater on to an unsealed surface. Wash all equipment on site on unsealed ground, away from stormwater drains.
[video: Sean in front of building site where some concrete has now been laid.]
Sean: Remember, you cannot filter out the pH from concrete wastewater so when disposing of it, use unsealed ground like gravel or grass, or have it collected by a waste contractor.
[video: Hose sucking wastewater at the edge of a recently concreted area. Worker using wetvac to suck dirty water at the kerb.]
Sean: Use a wetvac to suck up wastewater. Buy or hire a wetvac. It’s only a few hundred dollars to buy. It’s cheaper than a fine, and you can use it on job after job.
[video: Workers at the bottom of a sloped area they have been concreting, with truck at the top of the area.]
Sean: Or you can use a sucker truck to remove wastewater.
[video: Sean in front of building site.]
Sean: If something does go wrong, call council immediately. They’re there to help, and they can help limit any damage.
[video: Sean walks across the site to chat with a subcontractor. Sean points to an area of the site which they appear to discuss.]
Sean: Remember, you’re responsible for your subbies, so you need to check that they are following these guidelines.
[video: Sean.]
Sean: I hate to say it, but you’ll be held responsible if something goes wrong. And that can hurt your pocket.
[video: Four workers concreting. Concrete being smoothed by a tool.]
Sean: But if you follow the guidelines, you’ll save money on clean-ups and fines, you’ll have a clean site and you’ll keep our streams and sea clean as well.
[video: A sandy beach with woman powerwalking in the distance. Auckland Council logo. Music.]