pesuveden

Pesuveden is a Finnish term that translates to "wash water" or "greywater." It refers to water that has been used for domestic purposes, such as washing clothes, dishes, or bathing, but does not contain human waste. This distinguishes it from blackwater, which originates from toilets and contains fecal matter and urine.

Greywater typically contains biodegradable materials like soap, detergents, food particles, and hair. While less contaminated than blackwater, it can still pose health risks if not handled properly, especially if it contains harsh chemicals. The collection and reuse of greywater is a practice aimed at conserving fresh water resources and reducing the volume of wastewater sent to treatment facilities.

In many regions, including Finland, regulations govern the treatment and reuse of greywater. Simple filtration systems can remove larger particles, while more advanced methods can purify the water to a degree where it can be used for non-potable purposes such as toilet flushing, irrigation of gardens, or laundry. The specific treatment requirements and permissible uses of greywater vary by local legislation and the intended application. The sustainable management of greywater is increasingly recognized as an important component of water conservation strategies in urban and rural environments.