Updated database v. 2018-02-26

Updated database v. 2018-02-26

New data of zinc surfaces and copper surfaces, e.g. copper facades or roofs, zinc rails or roofs, which can be calculated in StormTac Web by using the land use “Own”, see Guide Description of land uses 2018-02-26.

Updated flow detention functions in serial facilities

Updated flow detention functions in serial facilities

Updated and revised functions have been developed for calculating required volumes for flow detention in serial facilities. These take into account factors for flow reduction in both previous and subsequent facilities.

The revisions affect both existing and new projects but do not make any changes in individual facilities and the first facility in a series of facilities.
They provide relatively small changes in subsequent facilities if the flow is not reduced as much between the facilities, but major changes if large flow is passed (no or less throttle) with greater flow detention downstream.

The functions take into consideration that, as before, the flow from the previous facility reduces the outflow up to some longer rainfall duration, after which all lower flows flow further downstream.
If long duration will be dimensioning downstream and there is strong flow reduction downstream, this may result in the upstream facility, in some cases, not will be as effective as you might think for reducing the required detention volume downstream.
This because a flow below the reduced flow could be dimensioning for long duration.
Then you can try to increase the flow reduction factor, which results in shorter design rain duration and reduces the required detention volume.
In practice, this means that you use a flow regulator in the outlet.
All this can now be simulated better than before by using the updated and revised functions.

Local, regional or country specific precipitation and rain intensities

Local, regional or country specific precipitation and rain intensities

Implementation of license customized yearly precipitation and rain intensities in Settings, so the user can start each new project with local, regional or country specific data.
Implementation of a method for calculation of rain intensities from regional input data from optional location in the World, by iteration of a regression coefficient.

Implementation of two new treatment facilities; dry ponds and…

Implementation of two new treatment facilities; dry ponds and sedimentation screen basins & revised coefficients for calculated reduction efficiency of the facilities biofilters, macadam ditches, swales and ditches

Dry ponds (ponds without permanent pool, with bottom outlet and dry between rain events) have been added as a new treatment facility in the biofilter box. Before, dry pond could only be designed for flow detention in the box Flow detention facility, or be designed as e.g. swales in the biofilter box. Now they can be designed for both treatment ad flow detention in the biofilter box.

Sedimentation basins (screens in ponds/wetlands or in the recipient water body) can now be designed in the wet pond box.
Descriptions appear in this box and in the box Reduction efficiency.
It is important to consider the lengt:width relation and that no extra effect for flow detention should be accounted for when calculating the reduction efficiency for screens in recipients, but else the design is the same as for wet ponds and wetlands.

Revised coefficients for calculated reduction efficiency of the following facilities and substances have been made after comparative studies of the data, and since more data have been added to the data base:

Biofilters: Pb, Cd, Cr, Ni, oil, PCP.

Macadam ditches: SS.

Swales: P, N, Pb, Cu, COD.

Ditches: P, Cu, Zn, Ni, SS, BOD.

This means that the calculated reduction efficiencies will be changed for the above facilities and substances for projects started after this release date.

2 added land use categories; marina and artificial turf…

2 added land use categories; marina and artificial turf fields

The two new land uses (small boat) marina and Artificial turf field have been added to the application and the data base, with standard concentrations for stormwater and baseflow respectively. The guide with description of land uses has been updated accordingly.

Complementary results at the bypass of peak flows past…

Complementary results at the bypass of peak flows past the treatment facility

In cases where flow detention is not in focus and the flows into the treatment facility are deemed to be too strong, it may be appropriate to bypass the peak flows past the treatment facility.

This update provides additional information in case of bypass.

In the flowchart and the results reports, are now not only the treatment effect, concentration and load of total transport presented, but also the treatment effect of the treatment plant itself, which concentration and load that flows into and out of the facility, respectively.

Design flow table

Design flow table

A new table has been added to the flow chart to the right of the value “Design flow for chosen return time” (l/s).
This table shows the flow (l/s) at different runoff transport times (min) and calculated design flow at the design runoff transport time (time of concentration, tc).

Do not forget to press ctrl + f5 to make a refresh of the page if something looks out of place.

Clarification and development of the Recipient model

Clarification and development of the Recipient model

For easier use, the management of input data in the box Recipient data has been clarified.
Depending on the substance, the criteria concentration for the recipient may refer to total, dissolved or bioavailable concentration.
Available measured data is filled in the box so that specified concentration (calculated or measured) in the recipient is used and corresponds to the fraction the criteria concentration is referring to.

In the box Water quality criteria, a criteria concentration for the specific recipient regarding phosphorus (P) can now be calculated.
The calculation is performed according to HVFMS 2013: 19. By using a criteria concentration (P) specific for the recipient, a better assessment of the load to reduce upstream is provided.

Updated database (v. 2017-11-15) for download

Updated database (v. 2017-11-15) for download

Updated database with many revised stormwater concentrations and new land uses

1. The stormwater and baseflow concentration data have been thoroughly supervised with comparison between land uses and revision to data from added case studies, resulting in changed stormwater data for certain pollutants for the land uses parking,residential area, vacation cottage development, downtown area, park grounds, atmospheric deposition, forest, agricultural property, meadow, wetland, golf course, railway embankment (also for baseflow), forest clearings, harbor zone, downtown area less and more polluted, industrial area less and more polluted, residential area less polluted, metal recycling center, roof, tank farm, junkyard, storing yard and pedestrian and cycling path.

2. New land uses have been added (to be implemented in StormTac Web before August 20, 2017):
– Vacation cottage development, permanent living
– Railway embankment in concrete, light train.