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2.1.7 Waste Water

Water management

There are great opportunities in using waste water as a resource; for irrigation and groundwater. Waste water management could provide an accessible and sustainable source of water, energy, nutrients and other materials fit for reuse.

The main documents regulating the rational use of water and in particular the use of waste water as a resource in Bulgaria are: the Water Act and the National Strategic Plan for Sludge Management from WWTPs. The basic principles set out in these documents are:

  • Water Law: Reducing Water Pollution, Improving the Condition of Aquatic Ecosystems, Prevention of Pollution - polluter pays.
  • National Strategic Plan for Sewage Sludge Management focusing on sludge recovery and sludge utilization;

Bulgaria generally shows a very low degree of compliance with the Urban Waste Water Treatment Directive (this also applies to the compliance rate of 11.6% and 11.2% for sewerage and secondary treatment respectively6,7.

The Strategy for Development and Management of the Water Supply and Sanitation Sector (WSS) in the Republic of Bulgaria 2014 – 2023 is the main “roadmap” for the development of the water and sanitation sector till 2023. It updates and sets out for consideration by the Council of Ministers the main objectives and priorities for the WSS sector in the Republic of Bulgaria. It also gives proposals for the implementation and financing of policies to achieve targeted objectives within a ten-year horizon. The strategy integrates the findings of consultations and intermediate analyses, including a regulatory review, public expenditure review, and strategic financing plan, produced and discussed with stakeholders since September 2012. Considering that many WSS capital investments have a long life time, both the expenditure needs assessment and the strategic financing plan were prepared for a 25- year time horizon. This provides assurance that the measures proposed in the ten-year strategy are in fact compatible with a sustainable WSS sector in the long term.

Main outline of the Strategy for Development and Management of the Water Supply and Sanitation Sector in the Republic of Bulgaria 2014 - 2023 is that water supply services largely meet standards, but water losses are high and water supply systems maintenance is insufficient.

Coverage of the water-supply system in Bulgaria is very high, and drinking water quality typically meets standards. More than 5,000 towns and villages have central water-supply systems. This represents 99 percent of the overall population. Drinking water quality meets standards more than 95 percent of the time in all large water supply zones. Problems remain with regard to compliance with standards, especially in the smaller water-supply zones.

The forecasted investment needs to achieve full compliance with the Directive in Bulgaria amount of 2.969 million euros. A major policy task recognized by the government is to ensure adequate urban waste water treatment and to establish a water pricing policy covering a wide range of services in the water sector and is based on a measure of consumption that stimulates the efficient use of water.

Introduction to water and waste water in circular economy

Using the water and waste water in the circular economy aspect is to promote greater resource productivity aiming to reduce waste water and avoid pollution. The material flows are of two types: biological nutrients, designed to re-enter the biosphere safely and technical nutrients, which are designed to circulate at high quality in the production system without entering the biosphere as well as being restorative and regenerative by design. This is a contrast to the linear economy which is a 'take, make, dispose' model of production.  So the purified wastewater can be used again, but as a result of wastewater treatment are formed –sludge and wastes from coarse and fine screens; grease and grit removal; sludge dewatering etc8.

The utilization of the sludge and wastes from WWTP’s is often a challenge. The reuse of sludge is depending and limited from the content of hazardous substances such as heavy metals in the sludge. To prevent entry of hazardous substances in WWTP sludge it is very important to control industrial wastewater before discharge in sewerage network.

The water and waste water sector have the potential to save more than  80 million Euro/yearly in Bulgaria by implementing different measures to reach 20% reduction of NRW.

The sector’s situation clearly justifies the need for a reliable financial plan for the short, mid and long term. The implementation of such a plan could only be ensured by carrying out deep reforms – a combination of measures and practices – which would result in specific amendments to the legislative and institutional framework and would enable the WWS operators to be direct beneficiaries of EU grants.

These would also improve the WSS operator’s possibilities for co-funding capital investment, including investment in WSS infrastructure, which is a public state and public municipal property. Review of the current policy and legislation (organization) is needed in order to allow profit to remain in the companies and be used for re-investing, increased tariff revenues and developing the regulator’s capacity.

The reform’s leading principles are:

  • Financial sustainability: providing sufficient and timely resources for the funding of the sector’s investment plan. 
  • Efficiency: optimization policies and practices to achieve compliance and cost-effective achievement of the objectives.
  • Affordability: resolving the issues related to tariff affordability through suitable social policies.
  • Predictability: WSS operators and the water regulator working together to achieve the sector’s main objectives.
  • Transparency: publishing data about the condition of the WSS sector and a comparative analysis of the WSS operators’ activity in order to encourage sustainable WSS practices.
  • Competitiveness and economies of scale: consolidation of, and introducing benchmarking of, WSS operators to enhance efficiency and service quality.

Below several opportunities are categorised and assessments have been made of these opportunities:

Opportunity 1/ Save and reuse potable water and high-value recycling of components and materials. This opportunity may bring the following benefits:

  1. Save new water resources and money for research and development of new water sources
  2. Save operation and maintenance expenses to produce water, transport of water, purification of water, treatment of waste water and sludge
  3. Healthy environment

Water companies can save water in other scales through reduction of NRW (non-revenue water), equivalent of “total water loss“, margined between produced and supplied water; reduction of physical loses; reduction of leakages from water supply network etc. here the management of water companies is responsible and a pressure with the “public opinion” is possible.

Opportunity 2/ Utilization of Sludge from WWTP: Reuse and high-value recycling of components and materials in sludge.

Benefits of implementing measures in that aspect:

  1. Use of valuable materials contained in the sludge (for fertilization. Rich on N, P.); save money for fertilization;
  2. Save O&M expenses for disposal in landfills;
  3. Healthy environment
  4. Return recovered bio resource to biosphere

Opportunity 3/ Using anaerobic digesters + CHP units (Combined Heat and Power) = Production of power energy during wastewater and sludge treatment.

  1. Save costs for power energy and for fuel for heating;
  2. Sell excess energy
  3. Increase effectiveness for using the methane for example selling power by top price periods.

Opportunity 3+/Using anaerobic digesters = Combined treatment of wastewater with other organic wastes with production of energy.

Benefits: Minimize expenses for separate treatment of waste and wastewater (Note: Legislation currently does not allow to treat waste und waste water together, because the financial rules for the two types of waste fall into two different regimes for funding.

Opportunity 4/Using of treated wastewater for recreation, fish- production, sport activities, tourism, restore health of ecosystem.

Opportunity 5/ Floodwater management; Storm-water management; (the precipitation has to be absorbed where it fell to the ground).


  1. Prevention of flooding damages;
  2. Save construction cost for Storm water drain/sewerage;
  3. Save Operation costs for treatment of storm water;
  4. Save construction cost – the WWTP for separate sewerage (only domestic wastewater)

Different instruments for POLICY INTERVENTION could be applied in Bulgaria:

  1. EDUCATION, INFORMATION and AWARENESS rising campaigns
  2. COLLABORATION PLATFORMS – like Green Industrial Symbiosis programme
  3. BUSINESS SUPPORT SCHEMES - to support innovation and new business models
  4. PUBLIC PROCUREMENT and INFRASTRUCTURE - initiatives to support circular procurement practices
  5. REGULATORY FRAMEWORKS - reduce NRW below 40%

Existing critical situations and vicious circles.

Opportunity 1: Save potable water in households and public sectors by reduction of NRW and honest pricing of water. For the new constructed WWTP and sewerage systems, the funds for depreciation have to be enough to rebuild a new infrastructure after the end of life. An effective way for monitoring the depreciations from water companies is missing. Most of the water companies do not increase the price of water services as planned during their application for financing.

Opportunity 2: Many WWTPs in the past years were rehabilitated or newly constructed with EU funding and mainly the projects have been implemented as a result of tenders and public procurement bids. But the disposal of WWTP’s sludge is still a problem, which needs to be solved. On the paper all new WWTP have a Sludge Management Plan (SMP), but very often the SMP is unrealistic and the sludge is an unsolved problem. WWTP’s sludge from big cities are polluted with heavy metals and cannot be used in agriculture. There are not enough landfills to dispose polluted sludge. The incineration of sludge is an option but it is expensive and not an environmentally friendly approach as well.

Opportunity 3: There are existing regulatory barriers to sell electric power produced from WWTP using CHP for small facilities. Electricity power sellers/distributors impose additional barriers for the smaller facilities. The expenses for separate treatment of wastes and wastewater could be optimized, but again legal regulations do not allow to combine treatment of wastes and wastewater.

Opportunity 4: Many WWTPs during the past years have been rehabilitated or newly constructed with EU funding. Mainly there is a usage of only “intensive methods for wastewater treatment and sanitation” and the “natural methods” as wet zones are excluded from the tenders. It is much more efficient for small towns and villages not to construct long sewerage systems and collectors and expensive WWTPs container types. In many cases the “Wet zones treatment plants” can be more suitable, because they have lower operation and maintenance costs, though a bigger area (construction site) is needed.

The rain water being streamed to soil absorption can be a more efficient solution instead of rain water being streamed to sewerage and combined sewerage system. The “Wet zones WWTPs” and absorption of Rain water into the soil are methods not included in the regulatory documents and difficult to be used in tenders and public procurement, thus being prevented from implementation.