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Storm water from 1,520 acres of Järvafältet north of Stockholm is treated by means of sedimentation in a 12 km long tunnel system with a volume of 275,000 m3. Storm water is thus given a long detention time before it is pumped out into Edsviken. Earlier a report has been given of one year’s pilot […]

The Stockholm Water and Wastewater Works have studied the needs for sewer rehabilitation to maintain an acceptable standard. The planning of the rehabilitation is being performed in three different steps. The first step was an overview in 1983 called ”The Stockholm Sewer System. Master Plan 1983”. It includes a summary of reported problems together with […]

Relaying water conduits and sewers in the conventional manner is an extremely expensive operation. In the central parts of Stockholm the price of relaying pipelines per metre is normally SEK 10,000. Although on the outskirts of the city the corresponding price is admittedly lower, somewhere about SEK 5,000, this too may be considered high in […]

Recently Stockholm’s two water treatment plants – at Norsborg and on the island of Lovö – have been completely automated and computerised. At the Lovö plant there is already a central computer with understations for steering and controlling the plant. At the end of 1985 corresponding equipment was ordered for the Norsborg plant from the […]

The location of the settlement that became the nucleus of today’s Stockholm was a success from the point of view of water supply. A huge boulder-ridge, which provided wells with abundant supplies of water, passed through Stadsholmen – the area now referred to as Gamla Stan. The esker enters the current city area at Norrtull […]

It is the task of Stockholm Water and Wastewater Works to operate water supply and sewage treatment plants and to be responsible for the pipeline systems for water and wastewater in Stockholm. The city’s first waterworks was commissioned in 1861, and it is only natural to assume that many aspects of the technical systems have […]

The possibility to reduce power consumption in aerated lagoons by means of a combination of mixers and aerators is discussed. Two theoretical examples based on recent studies in the US and experiences from aerated lagoons in Sweden and Tunisia are calculated to show the potential energy saving by using mixers and aerators in combination. The […]

Lagan är södra Sveriges mäktigaste vattendrag. IVL har på uppdrag av Lagans Vattenvårdsförening sammanställt en skrift till föreningens 30-årsjubileum. Skriften beskriver utveckling, utnyttjande och vård av ett vattendrag genom en tidsperiod som präglats av industrialisering, stora vattenvårdande insatser och ett ökande ansvar för bevarande av våra vattenresurser. Framtida beslut om vattenvårdande åtgärder blir svårare i […]

Phosphorus and nitrogen mass balances for the Baltic Sea are presented (mainly based on data from Larsson et al. 1985) for three situations: 1) present situation, 2) after 80 % P and N removal from point sources, 3) in natural conditions. The balances indicate that a phosphorus removal from point sources will lead to a […]

P removal from wastewaters by electrolysis was examined by an experimental laboratory system. Al electrodes were applied in accordance with previous experiments to find the best conditions (pH, water flow, energy consumption) for P removal. Alternating current with a frequency of 0.0039 Hz made ”self-cleansing” of the electrodes possible and provided a favourable energy consumption […]