Calcium filter beds

A focal area of ours is design and installatin of Calcium filter beds for removal of Phosphorus in ditches, streams and rivers. We have developed the technique and are in the front of development as well as implementation. Calcium filter beds currently constitute the only cost-effective action removing a large part of the dissolved Phosphorus fraction, mainly consisting of Phosphates, from agricultural drainage water. Dissolved Phosphorus is the main cause to eutrophication in lakes and in the Baltic Sea. Removal capacity and durability are evaluated in research projects conducted in co-operation with IVL Swedish Environmental Research Institute.


Assessment of the need for actions
In some areas existing monitoring data may give a sufficient basis for conclusions on whether a Calcium filter bed would be a cost-effective means to reduce Phosphorus pollution. In other areas an assessment of the upstream basin is required. We offer characterization of the basin, or sub-basin, in terms of percentage of arable land, management practices, soil types, husbrandry, presence and characteristics of lakes or dams upstream the location.

WEREC in most cases conducts the full design process, which includes:

  • Consultation of authorities
  • Registrations and permits
  • Geodetic measurements, design and construction plan
  • Plan for the construction work
  • Establishing agreements and contracts

We generally conduct the installation with in-house staff and in-house machinery. If needed, contractors are engaged. We then offer to carry out the procurement process as well as control and inspection of contractor work. We also procure the material required for the installation.

Management and evaluation
WEREC plans and conducts water monitoring programs for evaluation of the effectiveness and function of installed systems. We also provide management and operation of the installations, as well as substitution of the filter material. The operational costs are low, consisting of manual control and cleansing once or twice per year, and substation of the Calcium filter material every 7-8 year.