COMPLIANCE OF WASTEWATER TREATMENT PLANTS IN JÄRVA COUNTY WITH THE EU URBAN WASTEWATER TREATMENT DIRECTIVE AND ESTONIAN NATIONAL REQUIREMENTS
Annual International Interdisciplinary Conference, AIIC
COMPLIANCE OF WASTEWATER TREATMENT PLANTS IN JRVA COUNTY WITH THE EU URBAN WASTEWATER TREATMENT DIRECTIVE AND ESTONIAN NATIONAL REQUIREMENTS
Raili Niine 0
MA Enn Loigu 0
Prof Karin Pachel 0
0 Department of Environmental Engineering, Tallinn University of Technology , Tallinn , Estonia
The aim of this study was to assess the treatment efficiency conformity of Wastewater Treatment Plants to the Estonian and European Union requirements in the area of Estonian nitrate vulnerable zone as well as evaluate the existing national wastewater monitoring programme and the efficiency of the self-monitoring programme. Monitoring the results and total pollution load of effluent discharged to the receiving water body from 2007 to 2008 are used to assess the treatment level of WWTPs and the need to establish higher treatment requirements. Estonian national standards, due to the fact that Estonian water bodies are small and vulnerable to pollution, are stricter than the Urban Wastewater Treatment Directive (UWWTD) requirements. If the requirements given in UWWTD are not sufficient to achieve a good status for water bodies, it is proven that wastewater discharge adversely affects the receiving water body and this discharge is one of the important pointpollution sources for water bodies, additional stricter wastewater treatment requirements are needed. WWTPs with a more than a 2,000 population equivalent (p.e.) should be regulated vigorously to guarantee their compliance with the requirements, because WWTPs with more than 2,000 p.e. count for 80% of the total pollution load. A pollution load from WWTPs of less than 2,000 p.e. on the receiving water bodies is marginal; however, the extent of the impact of each individual WWTP depends on, among other things, the characteristics of the wastewater, the turbulence of the receiving water body and the area's sensitivity as well as other pressure sources.
Wastewater treatment; pollution load; effluent; receiving water body
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Introduction
In Estonia, Jrvamaa is one of the three counties that is designated a nitrate vulnerable zone
according to European Nitrates Directive (European Community (EC), 1991/1). According to
Regulation no. 17 of the Estonian Government, 2003, there is one nitrate vulnerable zone consisting
of two subareas Pandivere and Adavere-Pltsamaa. In Estonia, the rivers of almost all catchment
areas (excl. the islands) spring from the slopes of the Pandivere Upland karst area (Environmental
Report 7, 1993). In a nitrate vulnerable zone, all water bodies are highly affected by the non-point
sources from agriculture and are also easily influenced by point sources from wastewater treatment
plants (WWTPs) (Valdmaa et al., 2008). It is important to control the nutrient load, particularly
phosphorus pollution, even that of small settlements within agricultural and rural catchments (Jarvie
et al., 2006; Iital et al., 2010). Therefore, WWTPs have to comply with the discharge requirements
established by both the Urban Wastewater Treatment Directive (UWWTD) and the Estonian national
standards (ENS). The European Union integrated water policy main document, which establishes a
framework for EU actions in the field of water policy Water Framework Directive (WFD), sets a
goal to protect all waters against pollution and to achieve good status for all waters, promoting
sustainable water and wastewater management (European Community (EC), 2000; Ministry of
Environment, 2011). One of the most important surface water pressures is point-source pollution
(IMPRESS, 2002). Furthermore, the Baltic Sea countries adopted an action plan to achieve the good
ecological status of the Baltic Sea by 2021 (Helcom, 2007). One of the main issues covered by the
Baltic Sea Action Plan is the further reduction of nutrient inputs in order to limit the eutrophication of
water bodies. Estonian water bodies are sensitive to nutrients and have a high eutrophication risk. To
limit the eutrophication process, it is important to decrease total phosphorous (TP) and total nitrogen
(TN) loads. Several studies have researched the impact of WWTPs on receiving water bodies (Kontas
et al., 2004; Millier et al., 2011; Dickenson et al., 2011). For instance, Kontas et al. (2004) studied the
concentrations of inorganic nutrients, phytoplankton chlorophyll-, and N/P ratios before and after the
treatment plant. Dickenson et al. (2011) has reported on the presence of trace organic chemicals in
municipal wastewater effluents. This paper uses a set of common trace organic chemicals as
indicators to assess the degree of impact and attenuation of trace organic chemicals in receiving
streams. Also, other Baltic countries are considering the problem of phosphorus and nitrogen removal
from wastewater and, therefore, several studies have investigated the different methods of removing
nutrients from wastewater. One such study, Vabolien et al. (2007), evaluated the effect of (...truncated)