Construction site water refers to water or sludge generated at construction sites, excluding domestic waste water from social and sanitary facilities in site huts.
Construction site water is generated, for example, at:
earthwork construction sites
contaminated soil remediation sites
energy well drilling
building construction sites
foundation and yard work for buildings
Construction site water differs in quality from typical storm water in built-up areas. Compared to typical storm water, it contains many times the amount of solids, nutrients, and other harmful substances. It can cause turbidity in aquatic environments, reduced growth of aquatic plants, siltation of shores and bottoms, and suffocation of fish and spawn. Untreated construction site water can cause siltation, blockages, and corrosion of storm water sewers, manholes, pumping stations, and other structures, as well as waste water damage to properties.
Discharging untreated construction site water into watercourses is prohibited
Section 10 of the environmental protection regulations of the City of Hämeenlinna and the Municipality of Hattula concerns the treatment of construction site water. Construction site water and water from other temporary activities, such as energy well drilling, must not be discharged into watercourses, storm water sewers, or off-site without pre-treatment. Infiltration into the ground is permitted only if it does not pose a risk of soil or groundwater contamination. Discharge of construction site water into waste water or storm water sewers must be agreed upon with the water utility. The environmental protection authority must be notified before commencing activities involving the discharge or infiltration of construction site water containing significant amounts of solids or harmful substances, or with a pH value deviating from neutral.
Notify the environmental protection authority by email at kaupunkirakenne@hameenlinna.fi about the discharge or infiltration of construction site water containing significant amounts of solids or harmful substances, or with a pH value deviating from neutral. Submit the notification no later than 14 days before commencing your activities.
Construction site water guidelines
The Hämeenlinna and Hattula construction site water guidelines explain how projects and construction sites must address the discharge and treatment of construction site water to prevent harm to watercourses, small water bodies, sewer networks, waste water treatment plants, or the urban environment. The guidelines apply, as appropriate, to all construction and renovation sites that generate water requiring disposal.
The guidelines include an example management plan for construction site water in small-scale construction (Appendix 1), a construction site water monitoring document (Appendix 2), and a summary of the guidelines (Appendix 3). The guidelines are not binding regulations but provide guidance on good practices for construction site water management. The party undertaking the construction project is responsible for proper treatment of construction site water.
