Drain Smells? Chemiphase can provide a broad range of wastewater treatment odour control chemicals in their waste water treatment chemical range. All of these wastewater treatment chemicals come with our industry leading technical support. Chemiphase also offer a biological approach to odour control which is a long term treatment to eliminate the actual problem. A full list of our odour control chemicals waste water treatment chemicals can be found below. For more information on why your drain smells and what you can do about it, please contact us.