Sewage plant is a subsidiary of Kaunas Water
Supply Utility named Kauno vandenys Ltd. The plant
is situated on the edge of the city, called Marvelė,
on the bank of Nemunas river. It was started
in September, 1999, being the first sewage plant
in Kaunas history, despite of the fact that the
city is the second by size in the country with
population of 415,000. Up to this year, municipal
wastewater was simply issued to Nemunas. Treatment
on the Sewage plant is carried out by mechanical
and chemical systems. The main treatment
technology is anaerobic digestion of sewage. Also,
the sludge is processed by dehumidification
construction company KAUSTA built the plant in
1996-1999, using the loan from European
Reconstruction and Development Bank, EBRD. Because
of high quality of construction works and its
unique installations, the plant was awarded the
title of Best Lithuanian Product of the Year
(1999). The advanced techniques and special
equipment were used in the construction, including
equipment and experience of the Finland’s
largest corporation YIT
It enabled the company KAUSTA to reduce the
thickness of concrete walls from 150 cm to 40 cm,
being capable to withstand the same huge pressure
of sludge stored.
There are 4 sedimentation tanks installed, each of 52 m of diameter, and 4 methane-tanks, each of 18 m of diameter and 10,000 cubs of volume. The total capacity of plant is 232,000 cubs of wastewater per day. In a previous year the daily average issue of treated wastewater was 63,000-70,000 cubs. The digestion process is mezophylic one. Practically, only one methane tank is operated at present.
the purification capability achieved can be
described by following parameters:
of suspended matters:
78 - 83%,
of matters as BOD7:
60 - 67%,
70 - 82%.
removal of organic waste: 11- 14 tons/day.
combustion of biogas recovered in methane tanks
was started in June, 2000 in the own boiler-house
of the plant. The total output of biogas, 10,000
cubs per day, significantly exceeds the own
At present 28¬35% of biogas recovered is
burnt at the boiler-house in winter season, the
rest is burnt in a torch.
avoid a useless combustion of biogas in a torch, a
special project of biogas supply has been
implemented. It is a pipeline project which
provides the delivery of biogas to Noreikiškės
boiler-house owned by Kaunas district heating
company Kauno energija Ltd. Noreikiškės is a
settlement situated in a close vicinity of the
Sewage plant. It is planned to cover as much as 10
% of total expenditure of Sewage plant by income
from biogas sale to Noreikiškės
project has the following relevant parameters:
up 350 m3;
pf plastic pipeline: 110
pressure: 3 bar;
investment: 1 million LTL, split to
LTL for pipeline and route,
LTL –for compression station,
LTL – erection cost;
LTL – for receiver .
The pipeline was started in December, 2001. The Sewage plant sales the biogas to Kauno energija Ltd. by tariff 200 LTL/1000m3.
Lithuanian energy institute had analyzed the samples of waste water collected at Kaunas Sewage plant (2000). The laboratory tests and data processing lead to following results:
of dry organic matter in influent waste water:
2.19 – 3.34%;
same , in effluent waste water (at the outlet):
1.37 – 2.06%;
of CH4 in
of CO2 in biogas recovered:
of H2S in biogas recovered:
– 25 ppm;
output : 6000 – 10000 m3 /day;
value of biogas recovered:
25.06 – 26.85 MJ/ m3.
the analysis proved the high quality of biogas
As biogas recovery at the plant is expected to grow because of the biological treatment and network extension project, Lithuanian Energy Institute suggests to install the small-scale co-generation unit (CHP) at the plant. Own hourly peak demand of winter months ranges from 600 to 1,000 kW (thermal) and from 170 to 200 kW (electric). The input-output and efficiency parameters of recommended unit are as follows:
parameters of the project seem to be quite
costs (USD): 70,300
pay back time (year): 2.2
operating costs (USD/kWhel):
price (USD/kWhel): 0.0392
In 2000, Kauno vandenys Ltd started to implement the significantly bigger project, with a budget of 100 million Litas. The project is aimed at construction of biological treatment facilities and extension of city’s water supply and sewage networks. The idea of this project is to increase the input of wastewater to the Sewage plant by connecting the local water supply and sewage networks of neighbouring settlements and villages to city’s central networks, respectively. It will result in reduction of pollution of open waters and ponds by city’s waste water up to the level set by national environmental norm LAND 10-96. This norm was established by Lithuanian Environment Ministry and conforms to requirement of Helsinki Commission HELCOM. The recovery of biogas is assumed to increase significantly, as well as degree of waste biodegradation.
breakdown of investment is estimated to be 80
million Litas and 20 million Litas for biological
treatment facilities and extension of networks,
Lithuanian Council of ISPA had included the
project to the list of ISPA projects (ISPA is EC
structural instrument for pre-accession).
According to preliminary financing scheme, ISPA
provides a subsidy of 50 million Litas. Lithuanian
Government provides the second subsidy, 20 million
Litas. The rest part of project’s budget, 30
million Litas, will be covered by bank loan.
construction works will be started in midyear of
2002 and finished in 2004.