What characterizes Category 3 water treatment plants?

Category 3 water treatment plants are characterized by their use of a combination of coagulation and chemical softening processes. This approach is essential for treating water that may contain higher levels of hardness and suspended solids. Coagulation helps to aggregate particles, making it easier to remove them from the water, while chemical softening targets the reduction of hardness in the water by precipitating the calcium and magnesium ions responsible for mineral buildup.

The processes employed in Category 3 plants are crucial for ensuring the water meets safety standards and is suitable for public use. By combining these methods, plants can improve water quality effectively before it undergoes further treatment or distribution.

Regarding other choices, some involve methods or characteristics that do not define Category 3 plants specifically. For instance, solely using disinfection may not address the broader range of contaminants present in the water. Treating groundwater exclusively is not a defining characteristic, as various sources of water can fall under this category. Finally, reverse osmosis is a distinct treatment method utilized in different types of plants, often for specific contaminants, but it does not encompass the essential features of Category 3 plants.