Latvia, Svētciems

Historical background of Pilot site

First historical records about Svētciems are dated 1638, when a manor of Svētciems is mentioned. Settlement is located on the banks of salmonid river Svētupe, which in Latvian means Holy River. This hydronym derives from Holy caves of Svētupe, located approximately 15 km upstream of village. Nowadays settlement exists mainly as a supportive satellite of Salacgrīva town and harbor which is located 6 km northwards.

Quality of recipient water
River Svētupe is located in the protected site – North Vidzeme Biosphere Reserve, and is designated as Salmonid River. Therefore the more strict requirements for treatment of sewerage water are defined by environmetal authority.

Characteristics of water supply and wastewater treatment services provided

Existing wastewater treatment solution

Collected wastewater are treated by using biological treatment technology and is characterized as follows:

Wastewater treatment technology of existing WWTP

Problems to be solved
• The projected capacity are too large for currently produced wastewater loads. Therefore only one aero-tank is operated;
• Since WWTP was designed for bigger capacity and partial load was not expected for a long time, air blower power consumption is much more, then necessary;

• Existing concrete housing of WWTP is leaking, making secondary soil pollution;
• The wastewater treatment requirements set by the Regional environmental authority are reached not because of efficient treatment within aero-tank, but because of additional purification carried out in ponds having function of surface flow constructed wetland, which is not isolated from soil.

Effectivity characteristics of existing WWTP

Proposed solution
• Reconstruct biological WWTP with activated sludge, as cost effective and environmental more friendly solution the construction of new WWTP with appropriate capacity is designed on the land parcel of the old one;

• Since WWTP discharge is directed into Svētupe, which is salmonid water, additional phosphorous and total nitrogen treatment is advised, the technology is under design right now. The following alternatives are evaluated:

o Coagulant dosing to WWTP;

o Reconstruction of polishing pounds to wetlands;

o Cleaning of polishing pounds.

Technology for improved wastewater treatment

Expected effects
• Decreasing of power consumption;
• Significant decreasing of CO2 emission since WWTP automation, which will avoid everyday operator visits to check equipment status;
• Elimination of soil pollution due to leakages in WWTP and due to untreated wastewater inflow to non-isolated polishing pounds;
• Elimination of additional pollution of

Svētupe river salmonid waters

Current state of the pilot
The renovation of the outdated WWT facilities was initiated by Salacgrīva Municipality and evaluation of technical condition was done by University of Latvia, including sampling and analyses of influent and effluent wastewater and preparation of Feasibility Study. Project partners have been contacted to discuss best available technical solutions and Pilot sites in Lithuania and Poland was visited to select best technology for additional nutrients removal. Construction of new WWT facilities will be conducted in February-March 2018 and should be fully installed to start operate in April-May 2018.

What happens in the pilot
The impact of Svētciems WWT plant was assessed by taking samples starting from September 2016.

The pilot site were visited to evaluate condition and efficiency of existing WWT plant

Water utility “Salacgrīvas ūdens” were interviewed to identify existing problems.

Project Partners have been contacted to discuss best available technical solutions and Pilot sites in Lithuania and Poland was visited to select best technology for additional nutrients removal.

Due to the long technical design and wastewater treatment technology approval process with Reginal Environmental Board the construction of new wastewater treatment facility was started in late 2018.

During the building process pilot site was inspected by responsible state environmental authority.

The collected data clearly demonstrate environmental improvements of new wastewater treatment facility – the use of electricity has reduced significantly. Electricity consumption before (blue) and after (brown) introduction of improved wastewater treatment. 

The construction of pilot object was funded by the Interreg Baltic Sea Region Programme 2014-2020 and Salacgrīva District Municipality.