Projection and construction of WATER PURIFICATION MARSH

Presentation of the method

Water purification marsh is a circuit cleaning alternative. By constructing artificial wetlands to favor biological production nutrients are transferred to biomass in food chains dispersed to the surroundings.

The organisms making the reduction of nutrients possible are microscopic plants and animals giving a swarming wetland with high biological diversity.

Summer picture, Svenseröd
A water purification marsh is established on a slightly sloping land and adjusts to the character of the place. Every marsh is unique so special knowledge is needed for planning. The principle is a number of shallow ponds placed after each other where each pond represents an ecosystem. The water purification marsh can be used for cleaning of wastewater from one or many houses, for cleaning water from land runoff and agricultural runoff and as an extra cleaning step after a sewage treatment plant. The construction cost is low but a certain care to fulfill the function in the marsh is needed. The attention implies that leakage is avoided, no shadowing vegetation is allowed, the edges shall be trimmed. Specially before wintertime it is important to take away shadowing vegetation.

Winter picture, Svenseröd
In the water purification marsh there is a more effective reduction of nutrients than with traditional methods, with over 90 % cleaning of both nitrogen and phosphorous most of the year. In summertime and during dry periods when there is no outflow the cleaning is 100 %. The water purification marsh shall be constructed in a way that ice do not overflow in the surroundings in extreme winter situations when the whole marsh is totally frozen and ice is established. The nutrients are stored in the ice and as soon as it melts the biological production starts with the same high nutrient reduction as in the summer. The reduction of bacteria is at the same level as in the now often used methods for cleaning wastewater with different kinds of infiltration.

GM Vattenmiljö
Gunilla Magnusson
Herrestads Svenseröd 209
S-451 94 Uddevalla
Telephone: +46 (0)522 82085
Mail: gunilla.magnusson@vattenmiljo.se