Operational experiences

with humic substances

Beyblová S., Güntherová L.

Severočeské vodovody a kanalizace, a.s.

Introduction

• Company Severočeské vodovody a kanalizace, a.s.

• Drinking water sources Fláje and Meziboří

• Other drinking water sources

• Conclusion

Company Severočeské vodovody a

kanalizace, a.s.

• Our company is a leading provider of water management services in the North Bohemia ensuring the production and distribution of drinking water and sewage and waste water treatment

• Key figures: – 1,1 million supplied customers in Ústí nad Labem and Liberec regions

– 69 drinking water treatment plants

– 222 waste water treatment plants

– 1734 employees

– Total length of water main system: 9 606 km

– Total lenght of sewer system: 4 315 km

• Shareholders: – VEOLIA CENTRAL & EASTERN EUROPE S.A. .... 50,1%

– Severočeská vodárenská společnost a.s.(SVS) .... 49,1%

• SVS – All shares are held by 458 North Bohemian towns and municipalities

– The operation of water management assets owned by the Severočeská Vodárenská Společnost company has been entrusted, on the basis of a long-term contract, to the operating company – Severočeské vodovody a kanalizace, a.s.

Drinking water sources in North Bohemia

• Surface water

– Dams:

• Přísečnice, Kamenička, Křímov, Jirkov, Fláje – Krušné hory

• Chřibská

• Josefův Důl, Souš – Jizerské hory

– Rivers, Creeks – Bílý potok, Chomutovka

• Groundwater

– Litoměřice area – extraction wells

– Problems with drought

• Surface water quality problems – Humic substances, Manganese, Organisms

(Merismopedia sp., Asterionella, Peridinia), odour

Fláje Dam

• Krušné mountains (Erzgebirge)

• Volume: 21 600 000 m3

• Area: 153 ha

• Average long term flow (Q): 805 l/s

• Construction: concrete Noetzli type

• Lenght of the crown: 459 m

• Hight of the dam: 49,46 m

• Outflow horizon for treatment: 1

Raw water quality - COD

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COD [mg/l]

Raw water quality – Humic acids

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Humic acids [mg/l]

Raw water quality – Temperature

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Temperature (°C)

Treatment Plant Meziboří

• It was built between 1954 - 1963 as part of

comprehensive water project Fláje (Fláje dam on

the Flájský creek, the feeder into the

equalization tank at the end with power plant,

water treatment Mezibori and supply system).

• Its max capacity was 800 l/s, after reconstruction

(2012 - 2015) it is 550 l/s (1980 m3/hour)

• The biggest issues – humic substances,

manganese, treatment of cold water during

winter

• Treatment plant supplies drinking water to the

city of Most, Litvínov, Duchcov, Teplice, Bílina,

and partly regional town of Usti nad Labem

• Over 125 000 customers

Treatment Plant Meziboří

Fláje Dam

Reaction Tank

Flotation

Filtration

Drinking water

reservoir

Lime

Coagulant

Flocculant

Carbon dioxide

Ammonium sulphate Chlorine

Lime

Waste water

Treatment Plant Meziboří - General

reconstruction

• The overall reconstruction in 2012 – 2015

• Cost - 8 800 000 Euro

• Intensification of the treatment plant was divided into two parts.

– The first with a duration of 20 months and performance limited to 270 l/s included the

reconstruction of the inflow building, construction of engineering buildings, reaction tanks and

flotation, reconstruction of pumping stations, reservoirs of treated water and chemical

management.

– The second part with a duration of about 14 months and performance limited to 180 l/s included

the reconstruction of the sand filtration, storage of treated water 4 x 2125 m3, completing the

control system of technological processes and chemical management. There was also overall

construction renovation of the treatment facility.

DAF – Dissolved Air Flotation

• Dissolved Air Flotation (DAF) is a

separation process that is included as

the first separation stage in the

drinking water treatment process.

• Suspended substances (flocs,

particles, organisms) join the air micro-

bubbles in the contact zone to be

brought up to the level of the

separation zone where they form

floating layer of a mechanicaly

removed sludge foam.

• High separation efficiency

Filtration

• New underdrain system - Leopold®

Type S™ technology underdrain

• Leopold Type S Technology

Underdrains feature closely spaced,

non-clogging orifices for uniform

distribution of air and/or water

backwash. This does more than

promote trouble-free operation. It

cleans the media better.

• Proven flow distribution

• Sand - height of fill: 1,7 m

Přísečnice Dam

• Volume: 46 670 000 m3

• Area: 362 ha

• Average long term flow (Q): 960 l/s

• Construction: Earth type

• Lenght of the crown: 469,7 m

• Hight of the dam: 47,2 m

• Outflow horizon for treatment: 4

• Low humic acids, problems with odour

– irregular incidence of Actinomycetes

• DWTP Hradiště

• Max capacity was 1050 l/s, after

reconstruction (2006 - 2008) it is 800 l/s

(2880 m3/hour)

• Drinking water for Chomutov, Kadaň,

Klášterec, Louny, Most, Teplice

• Over 240 000 customers

Souš Dam

• Jizerské hory (Isergebirge)

• Souš DWTP max. 240 l/s

• Drinking water for Jablonec nad Nisou

• Over 70 000 customers

• Humic substances, snow water, very low pH

• Liming of the dam

• 1st separation stage – DAF (2014)

Liming – cca 100 ton of lime

• Humic substances are a long term problem.

• Changes of raw water quality – seasonal changes, Irregural incidence

of organisms and others

• Instalation of 1st separation stage (DAF) – high separation efficiency

• Further research and cooperation of state and private sector is

necessary

Conclusion

Thank you for your attention