When you are working with concrete, it is important that you make sure that the slurry is disposed of safely. Concrete slurry can be quite harmful to the environment, so it is important that it is processed in a way that ensures the silica dust does not get dispersed in to the environment.
The majority of concrete slurry is water, and in the ideal world we would retrieve that water, and treat it so that it can be re-used. This can be done by filtering the dust out of the slurry, and draining the water out. It is important to reduce the pH of the water as well so that it is neutral and safe. Water separation is not a requirement for safe slurry disposal – as long as the dust is not allowed to make it into our waterways – but it is good practice. The solid, dry slurry is legal and in compliance with EPA standards. Dry slurry can be taken to landfill assuming that it is free from toxins – which most are. There are some concerns that certain forms of solid slurry are not safe – because they contain toxins that may leach into the environment. Some landfills will ask to take a sample of the solid slurry to use for chemical analysis to confirm whether it is safe, and then will tell you what you can do with it after checking the chemical makeup. If you solidify a slurry with a product that contains heavy metals, then this could be a problem for you. Dealing with concrete slurry can be a complex issue, but using a separator instead of a solidifying agent is a practical and easy solution that will allow you to manage the slurry safely and efficiently on site.
Concrete slurry cleaners are useful to dry out slurry and to make it safe to dispose of. The environmental protection agency has rules about how concrete slurry can be disposed of, because the slurry contains silica dust which could be dangerous if it is allowed to make it into our waterways. The slurry can be hardened using a number of different agents (but these can be dangerous in their own right because they contain heavy metals that can be toxic as well), or can be treated using a cleaner or separator to get rid of the water in them leaving a dry dust that is comparatively inert.
After water is removed from the slurry, it can be neutralised and filtered so that the water is safe for re-use.
Concrete slurry can be hard to dispose of. Not all landfill agencies will take it – even in powdered form – without doing chemical tests to make sure that it is safe. Slurry in liquid form can be incredibly dangerous to wildlife, and can run off and pollute waterways as well. A concrete slurry cleaner will help to protect the environment, and will make things safer for you.
The Toxicity Characteristic Leaching Procedure that the EPA requires be performed to test slurry is something that builders should familiarise themselves with to ensure that you do not accidentally try to dispose of slurry that could carry heavy metals out of it and leech into landfill. The disposal process may not be easy, but don’t try to save a few minutes now by disposing of potentially dangerous slurry when there could be long term ramifications that could leave the environment struggling with the after effects for many generations after you are gone. We only get one earth, take care of it.