Estimation of the wastewater generation by the branches of industry Statistical Office of Estonia Environment and Sustainable Development Statistics Service

Background The Eurostat/OECD Joint Questionnaire on the State of Environment, part Water asks data for wastewater generation and loads of pollutants (BOD, suspended solids, N-tot, P-tot) in discharged wastewater by economic categories. Up to present there was no data available on the wastewater generation by the sector industry.

Tasks Find the wastewater volume by selected industries by NACE codes Estimate pollution load (BOD, suspended solids, N-tot, P-tot) in generated wastewater by NACE codes Estimate quantity of pollutant (BOD, suspended solids, N-tot, P-tot) in wastewater released into environment originated from industries by NACE codes

Sources 1.Report and database of Estonian Environment Information Centre (EEIC) Water management 2. Survey of Statistical Office Water management 3. Database of wastewater treatment plants

Statistical Office additional survey Survey population All industrial enterprises which have not produced environmental report but have produced the PRODCOM statistical report were surveyed related to water management AIMS Reach the full coverage of industrial sector on NACE 2digit level on water use (by purpose types) and wastewater generation Figure out the quantity relationship between the water use and wastewater generation on NACE 2 digit level

Enterprises were handled in two categories: THE REAL DATA ON WASTEWATER GENRATION WERE USED for the enterprises who presented data on water use and wastewater generation THE DATA WERE ESTIMATED ON THE BASES OF NET SALES for the enterprises who did not present data on water use and wastewater generation

Wasteater factor: Amount of generated wastewater, m3 _____________ Net sales, kroons Estimation of the missing data in Statistical Office survey

Principles for the estimation of generated wastewater quantities by economic activities (NACE group) Statistical Office survey results Estimations of wastewater quantities on the bases of EEIC database on water use Estimations for missing wastewater quantities based on monetary factor Waste water quantities For each economic activity group: wastewater quantities by types

Waste water generated as the sum of the discharges of three enterprise categories NACE m3 EEIC- grey Estimations-white Statistical Office survey-black

EEIC- grey, estimation-white, Stat office survey-black Waste water generated, the share of discharges of three enterprise categories in total of the economic activity

The estimation of pollution (P, N, BOD, suspended solids) in industrial wastewater was performed in two locations of the wastewater flow: Generation Discharge to environment...for each economic activity group, NACE 2 digit level...

Allocation of the pollution loads of wastewater discharged to the environment by economic activities was performed using average loads and quantities of generated wastewater Total pollution quantities in waste water Cooling water pollution load Industrial and sanitary waste water pollution load Average load directed to environment: BHT7: 18,6 total-N: 35, 0 total-P: 2,1 suspended solids: 27,9 Average load directed to environment: BHT7: 3,8 g/m3 total-N: 2,4 total-P: 0,1 suspended solids: 13,2...for each economic activity group... All wastewater released into environment have the same pollution load

Calculation of generated by indstry sector wastewater loadings, before treatment Wastewater treatment plants inflow monitoring data were used for the calculations of the generated wastewater pollution parameters

Presumption: One inhabitat consumes daily in average 127 litres water and generates the same amount of wastewater (expert opinion) Wastewater treatment plants were devided 1) URBAN 2) Other (industrial included)

Urban treatment plants Other treatment plants Industrial water Inhabitants water Pollution concentration BOD 318,0 g/m3 Susp sol 384,9 g/m3 Tot N 61,9 g/m3 Tot P 12,9 g/m3 Pollution concentration BOD 301,3 g/m3 Susp sol 262,8 g/m3 Tot N 61,4 g/m3 Tot P 12,7 g/m3 For industrial and inhabitants wastewater the summary quantities and average pollutants concentrations were found

For the allocation to the NACE categories the pollution quantities of the generated wastewater, the following presumptions were made: Pollution loadings in Wastewater originating from industry are distributed proportionally to the generated wastewater quantities. Pollution loadings concentrations of Sanitary wastewater originating from industry are considered to be equal to the inhabitants wastewater parameters

Wastewater generated by economic activities, quantities, BOD, susp, N, P

Conclusions