Små avlopp- ett litet problem I Danmark?

Transcription

1 Background for the regulation in Denmark It is the receiving water, that decide the level of purification Små avlopp- ett litet problem I Danmark? Inge Faldager Danish Technological Institute, Denmark In 199 the receiving water in rural areas were polluted 0% of the rivers and 2/-/4 of the lakes did not fulfilled the requirements special law was prepared for improving the condition of receiving waters in rural areas 1 2 Classifications for the purification Who is paying? How big is the problem? Purification class BI Total fosfor Nitrifikaion SOP 9 % 90 % 90 % SO 9 % 90 % OP 90 % 90 % O 90 % O: Reduktion af organisk stof OP: Reduktion af organisk stof og fosfor SO: Skærpet krav til reduktion af organisk stof samt nitrifikation SOP: Skærpet krav til reduktion af organisk stof og fosfor samt nitrifikation Purification classes Demands for substance reduction in different purification classes 1. The owner pay, and have the responsibility for the plant 2. The owner choose to be a member of the sewer company. The sewer company pay the installation, and do the maintenance. The owner pay to be connected (2.000 Danish kr.) and a tax pr. m wastewater every year In Denmark we have single properties in the open country will be asked to improve their sewers Implementing of the water frame directive will add properties It have to be finished in 201 We will not reach it 4 6 1

2 Possible solutions Pressure sewer systems Soil infiltration systems Sewer systems (pressure sewer systems) (SOP) Soil infiltration systems (SOP) Mini waste water treatment plants (from S to SOP) Sand filter systems (SO) Willow plants (SOP) Soil/plant systems (SO) Others (Filtralite) (SO) 8 9 Soil infiltration systems - Infiltration not posible Water supply-drill 00 m Clay Mini waste water treatment pants Danish Type pproval of Mini waste water treatment pants CE-mark is not sufficient in Denmark Mini waste water treatment plants must have a danish type approval which is much more strict then the CE-mark 4 plant have to be tested during 1 year in Denmark in the field under supervision from a impartial body 4 plant have to be tested during the apporval periode by impartial body The type approval is valid for years If the quality of the outlet is poor the type approval is withdrawn

3 Danish Type pproval of Mini waste water treatment pants When approved a service-visite 1 time/year is mandatorial - payed by the owner Sand filter systems Willow plants During this visite a sample is taken result is sendt to municipality 4 plants are appoved in Denmark Willow plants 8 m 8 m 1,1 m 1,1 m 1,1 m 1,1 m 0, m 1,1 m 1,1 m 1,1 m 1,2 m 1,1 m 0, m FORDELERRØR TØMMEDRÆN MEMBRN 1, m FORDELERRØR TØMMEDRÆN MEMBRN 1, m m m

4 Soil/plant systems Other types of plants Problems with septic tanks in Denmark CEN TC 16 / WG 41 NTURren-plant Many septic tanks are collapsing when the ground water is high The deviding walls are soft and so low, that floating sludge can pass over Many tanks can not be emtied because of bad construction or small extension shafts Nobody is controlling the tanks Only a few manufacturers have CEmarked there tanks, and there were no demands for stregth and hydraulic capacity Small wastewater treatment systems < 0 PT Overview 1 or or 4 C C 6 (B) D E E 2, 1,, 4, 6, Code of Practice Harmonized product standard 22 2 and Fred Nyberg E 4

5 From 2011 the requirements in Denmark are: ll requirements in EN shall be fulfilled The result from the hydraulic test shall be max g. Extension shafts of min. 00 mm up to 6 m and 80 mm for tanks over 6 Structural behaviour: groundwater table at ground level and depth of outlet 1, meter under ground level Level between inlet and outlet mm Dividing plates in the tank must be 200 mm above water level ll requirements must be documented by a accredited laboratory Since 1982 Sweden has had standards for septic tanks, including testing of their hydraulic function. In Sweden the requirements are: ll requirements in EN or -4 shall be fulfilled The result from the hydraulic test shall be max g. (Structural behaviour: groundwater table at the top of the tank and the tank top at least 1,0 m under ground level) Level between in- and outlet 100 mm fulfils non surcharge requirement ll initial type testing must be documented by an accredited laboratory Most requirements already came in re we sure of the quality? Denmark has national guidelines for all the normally used types of plants Denmark has a compulsory type approval for mini waste water treatments plants, that goes beyond the CE-mark Denmark has demands on septic tanks, that goes beyond the CE-mark Denmark have compulsory authorization for all contractors working with private sewer systems We are quite sure of the quality Thank you for your attention 28