03.04.2019 Variations in industrial wastewater composition at inflow of wastewater treatment plant «Daugavgriva», Numbers and Facts

Information about SIA «Rīgas ūdens» 2018 • Riga city service territory 307 km2 • Riga citizens 677 295 connected to town water&sewage network 619 703 PE - 701 534 • Clients – 15 000 • Drinking water supply 39,147 million/m3 • Treated wastewater 47,540 million /m3 • Financial turnover 45,6 million /EUR • Employees 772 EU co-financed projects Project «Development of Water Management in Riga, 5th stage» 2018 – 2019 Planned activities of the Project Project funding in Berģi, and Beberbeķi: 26, 07 million/EUR Including Cohesion • New Sewerage network 34,59 km; fund cofunding • Sewer network reconstruction 0,44 km, 9, 93 million/EUR • 18 new Sewerage Pumping Stations.

In addition to 2014-2020 period planned activities of 24,73 km new centralized water supply networks will be built and 0,41 km reconstructed (financed as project non-related expenses). Planned project period is 69 months with the deadline on 31th December in 2023 Investments

Main investments in drinking water and sewer networks

Investment type 2016 2017 2018 Water network rehabilitation ~ 0,9 km ~ 8,2 km ~ 3,6 km Gravity sewer rehabilitation ~ 3,4 km ~ 10,7 km ~ 9,9 km Pressure sewer rehabilitation 0 km ~ 1 km ~ 8,9 km

Fire hydrants replaced 510 483 472 Valves replaced (DN≥100 mm) 1447 1133 1010 Water supply network Water Supply Riga city Remberģi Centralized water supply system Baltezers-1 scheme in 2019 Baltezers Baltezers-2 Zaķumuiža RĪGA

1 416 km water supply network 15 water pumping stations

01.12.2017. WWTP “Daugavgrīva” WWTP “Daugavgriva” (1991) PE 750 000 to 1 million Average flow 150 000 m3/day

[email protected] 26.03.2019 WWTP “Daugavgrīva”

Key Performance Indicators(2018)

47 540 576 m3 of treated wastewater

40 865 t of sludge production

Treated wastewater costs 0,33 EUR/m3

9 100 150 mg/l200 250 300 350 400 50 mg/l 10 0 0 1 2 3 4 5 6 7 8 9 WWTP “Daugavgrīva”WWTP 6.3 171 1999 3.2 1999 32 2000 7.62 2000 199

2.88 16 Riga WWTP " 7.6 221 2001 3.3 2001 19 Riga WWTP " 7.3 214 2002 3.2 2002 15 7.8 227 2003 2.6 2003 18 8.6 273 2004 2.9 2004 23

8.6 264 Daugavgriva 2005 3.6 2005 33 277

8.8 Daugavgriva 2006 2.7 2006 21 7.8 2007 277 2007 2.9 16 8.4 2008 280 2008 2.5 35 8.8 2009 11 260 2009 1.0 "

258 SS 2010 7.8 2010 7

0.7 P tot. " concentration

9.4 2011 311 concentration 2011 0.6 7 7.5 2012 268 2012 1.2 9 7.5 2013 250 2013 0.9 9 7.5 2014 297 2014 1.1 14 8.1 2015 305 2015 1.15 13 8.0 2016 332 2016 0.8 7 7.98 2017 333 2017 0.72 8.7 385 8.92 2018 8.5 2018 0.67

10.0 20.0 mg/l30.0 40.0 50.0 60.0 70.0 mg/l 0.0 100 150 200 250 300 350 400 50 0

30.0 1999 15.6 145 1999 12.2 2000 36.9 21.1 199 Riga WWTP " 2000 9.8 41.6 2001 22.4 189 2001 10.4 43.5 2002 22.2 208 2002 10.5 50.1 2003 30.5 232 2003 10.6 52.1 2004 24.2 249 2004 16.0 Daugavgriva 49.4 2005 27.7 244 2005 21.8 54.3 2006 38.5 257 2006 13.6 51.9 2007 39.4 260 2007 16.6 55.2 2008 293

40.6 " 2008 17.8

57.7 BOD5 2009 22.4 298 2009 7.9 55.0 2010 18.6 273 2010 6.9

58.8 concentration 2011 21.0 255 2011 7.3 2012 53.8 248 20.2 2012 10.9 2013 52.0 266 11.2 2013 9.9 2014 55.9 273 9.0 2014 10.6 2015 57.6 282 8.9 2015 10.2 2016 50.2 275 8.9 2016 8.5 55.1 2017 7.05 2017 278 11 9.6 2018 65.30 323 7.22 2018 8.7 WWTP “Daugavgrīva”

Treated effluent volume (mln.m3) 1999-2018 Production of sludge 1999-2018 (tonns)

60000000

50000000

40000000 3

m 30000000

20000000

10000000

0

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018

Production of biogas 1999-2018 (mln.m3) Treatment efficiency % WWTP “Daugavgrīva”

29 WWTP “Daugavgrīva”

Riga Water wastewater treatment WWTP Daugavgriva performance data 2018

Average Average Pollution Latvian concentrations concentrations regulation load to Baltic Parameter inlet to WWTP effluent sea Nr.34 2017 2017 (tons/year) (mg/l) (mg/l) (mg/l)

N tot. 65,3 7,22 10 344

P tot. 8,92 0,67 1 31

BOD5 323,1 8,7 25 415

SS 385,1 8,5 35 405 20 Wastewater network Wastewater treatment and collection

Riga city Centralized Sewage system Notekūdeņu savākšana un in 2019 attīrīšana

KSS 307 WWTP Daugavgrīva

RĪGA KSS 106 KSS 311

1 143 km Sewage network 85 Sewage Pumping stations

01.12.2017. Legislation Riga City Council Binding Regulations No.17 Binding regulations of operation, use and protection of Riga city centralized water supply and sewerage system

Maximum permissible concentration (MPC) Pollution mg/l SS 450,00 COD 700,00 N tot 46,00 P tot 9,00 Extractable substances 40,00 Oil products 4,00 Surface active agents 5,00 Cr 0,40 Ni 0,40 Zn 0,30 Cu 0,20 As 0,02 Pb 0,20 Hg 0,01 Phenols 0,1 Formaldehyde 0,5 Cd 0,01 Types of monitoring used by Riga Water:

Ambient monitoring (existing…) • Status and trend detection • Testing of wastewater pollutants • Calculation of loads

Effluent monitoring WWTP Daugavgriva (existin….) • Calculation and control of discharge standards • Monitoring of plant performance

Operational monitoring WWTP Daugavgriva (existing…) Monitoring for operation of wastewater treatment works.

Early warning (Riga sewage network/WWTP-developing 2017/2019)

14 Riga Water levels of wastewater pollution monitoring (where we are….)

Simple monitoring based on a limited number of samples, simple analysis or observations, and obtained data treatment (.....excel)

Intermediate-level monitoring requiring more variables, stations, and specific laboratory equipment and PCs/software for data handling

Advanced level monitoring involving sophisticated techniques and highly trained technicians and engineers for sample analysis and data handling, often using mainframe computer systems.

15 Intermediate-level monitoring (on-line) More variables - TSS, COD, BOD, TOC, DOC, NH4-N, NO3-N, TDS, Conductivity, pH, temperature - inlet chamber WWTP Daugavgriva, main pumping stations (3-4) and specific laboratory equipment and PCs/software for data handling, via online.... Advanced level monitoring (2018 -2020) Involving sophisticated techniques (on-line data from town sewage network) and highly trained technicians and engineers for sample analysis and data handling, using mainframe computer systems. Wastewater Network Modeling and Analysis Solution CAPABILITIES:

Analyze hydraulic performance of flow rate > dilution of pollutants. Use a hydraulic model and wastewater GIS.

Analyze hydrogen sulfide formation

Determine sewer overflow risk

Identify areas of inflow and infiltration

Simulate wastewater concentration Situation today:

Inhibition

Nitrification works with two groups of nitrifying bacteria, AOB (ammonia oxidizing bacteria) and NOB (Nitrite oxidizing bacteria), are sensitive to booths substrate of their own and each other. Antohnisen et.al. 1976. They are autotrophic, as they oxidize inorganic nitrogen and use it as an energy source.

SUMMARY:

1. Industrial wastewater monitoring programm via check list/investigation relates to Eco toxicity (OSPAR, EU Toxicology of Chemicals report No. 80 – ECETOC 2001);

2. Nitrification inhibition definition for monitoring points (Inhibition index - for sewage network& WWTP Daugavgriva - Inhibition %) accordingly to EN ISO 9509:2006. Water quality – Toxicity test for assessing the inhibition of nitrification of activated sludge 1 microorganisms. Inhibition index (Inh i=MECmax /PECLD50), when <1 no environmental risk?

• Analysis of Free Ammonia - Inhibition of Nitrite Oxidizing Bacteria (RTU, UITK 2018- 2019); AOB, NOB?

3. Wastewater Network Modeling and Analysis Solution (Bentley®) Dilution rate?

4. Early warning «on line» information system for shock loads and toxic substances. Thank you for your attention!