Ukkadam STP, Coimbatore, Tamil Nadu

Ukkadam STP, Coimbatore

Co-treatment Case Study
Contents
List of Tables ................................................................................................................................. 1
List of Figures ................................................................................................................................ 1
A. City Profile ................................................................................................................................. 2
B. Co-treatment – Genesis ............................................................................................................. 3
C. Co-Treatment at Ukkadam STP .................................................................................................. 5
Plant Background .......................................................................................................................... 5
Planning and Implementation of Septage Co-treatment ................................................................ 6
Volume and Quality of Septage ..................................................................................................... 6
Infrastructure Investments and Operational Changes for Co-treatment ......................................... 6
Financial Details ............................................................................................................................ 7
Performance Details ...................................................................................................................... 8
D. Impact of Co-treatment ............................................................................................................. 9
E. Key lessons and practices .......................................................................................................... 9
Annex I: Coimbatore – Population (Census 2011) ............................................................................ 11
Annex 2: Status of access and collection and conveyance systems in Coimbatore............................ 12
Annex 3: Details of Ukkadam STP .................................................................................................... 13
Annex 4: List of officials met at Coimbatore..................................................................................... 14

List of Tables
Table 1: Sewage Treatment Plants (STPs) in Coimbatore ................................................................... 3
Table 2: List of Rules set by CCMC for private desludging operators partnering in co-treatment at
Ukkadam........................................................................................................................................... 4
Table 3: List of documents to be submitted by private operators while entering into an agreement
with CCMC ........................................................................................................................................ 5
Table 4: Charges for co-treatment – Tipping Fee ............................................................................... 8

List of Figures
Figure 1: Access to toilets in Coimbatore ........................................................................................... 2
Figure 2: TSS levels (inlet and effluent) mg/l ...................................................................................... 8
Figure 3: BOD levels (inlet and effluent) mg/l .................................................................................... 9

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 Ukkadam STP, Coimbatore, Tamil Nadu

A. City Profile
Coimbatore, the second largest city of Tamil Nadu1, is located on the banks of River Noyyal. The city
is a major industrial2 and educational hub of southern India.

In 2011, the jurisdiction of Coimbatore City Municipal Corporation (CCMC) was expanded to include
three Municipalities3, seven Town Panchayats (TPs)4 and one Village Panchayat5, thereby increasing
its area from 105.06 km2 to 257.04 km2. As per Census 2011, CCMC (post expansion) had a
population of 1.61 million. (For details of population of erstwhile CCMC and newly incorporated
areas refer Annex 1). As per the City Sanitation Plan (CSP), the city’s population is expected to reach
2.15 million in 20256.

Access to toilets: As per Census 2011, 87.80 Open

percent of households in Coimbatore had Defecation
access to Individual Household Latrines 2.50%
Public
(IHHLs) and 9.7 percent were using public Toilets
toilets7. (Figure 1) Approximately 2.5 percent 9.70%

of the households were defecating in the

open. (For detailed refer Annex 2)
IHHLs
Under the Swachh Bharat Mission – Urban 87.80%
8
(SBM-U) 4,862 IHHLs were constructed,
taking the proportion of households with Figure 1: Access to toilets in Coimbatore
9
IHHLs to 90 percent . In addition 58 public /
community toilets (known locally as Namma toilets) were constructed, taking the number of public /
community toilets to 37110. As a result of these initiatives, Coimbatore was declared Open
Defecation Free (ODF) in December 201711.

Sewage collection, conveyance and treatment systems: Only 37 percent of households with IHHLs
were connected to the piped sewer network in 201112. Majority of the households with IHHLs were
based on on-site collection systems including septic tanks (57 percent) and pit latrines13 (5 percent).
(For details refer Annex 2)

The CCMC area is only partially covered with Underground Sewerage System (UGSS). As per CCMC
only 22 percent (approximately 23 km2) of the area under erstwhile CCMC14 is connected to UGSS.
The remaining parts of the erstwhile CCMC and recently incorporated areas (3 municipalities, 7 TPs
and 1 VP) are not covered by UGSS. Discussions with CCMC officials revealed that work for covering

1 After Chennai; As per Census 2011 Chennai had a population of 7.1 million.
2 Key industries contributing to the city’s economy are textiles, automotive components, software services, manufacturing,
education and healthcare. Coimbatore also houses the country's largest number of hosiery and poultry industries. The city has two
special economic zones (SEZ), the Coimbatore Hi-Tech Infrastructure (CHIL) SEZ and Coimbatore TIDEL Park, and at least five more
SEZs are proposed.
3 Kavundampalayam, Kurichi and Kuniamuthur Municipalities
4 Chinnavedampatti TP, Kalapatti TP, Saravanampatti TP, Vellakinar TP, Thudiyalur TP, Vadavalli TP, and Veerakeralam TP
5 Vilankurichi Village Panchayat
6 Source: City Sanitation Plan submitted to Swachh Bharat Mission, GoI.
7 The city had 313 public toilets
8 The target under SBM-U was to construct 6056 IHHLs, in FY 2018-19 approximately 1500 IHHLs are planned to be constructed.
9 Source: CCMC Budget 2018-19
10 Prior to SBM U there were 313 public toilets. Source: CCMC Budget 2018-19
11 Source: CCMC
12 Source: Census 2011
13 Including pits with slabs / Ventilated Improved Pits (VIPs) and Pit without slab /open pit
14 The sewer lines extend for 162 km

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 Ukkadam STP, Coimbatore, Tamil Nadu

the entire area of the erstwhile CCMC (105.06 km2) with UGSS is underway. This will still leave the
newly incorporated areas with a population of 0.544 million unserved by UGSS.

CCMC is divided into three zones for sewage collection, conveyance, treatment and disposal. The
city has 3 Sewage Treatment Plants (STPs) namely, Ukkadam, Ondipudur15 and Nanjundapura16 with
total installed capacity of 170 MLD. While the city has three STPs, only one, namely, Ukkadam is
currently operational. Thus, at present, the city’s wastewater treatment capacity is only 70 MLD.
Table 1 summarizes the installed capacities, treatment technology and the current flows received at
the STPs.

Table 1: Sewage Treatment Plants (STPs) in Coimbatore17

Zone Location Capacity Current Waste Treatment Technology
[MLD] water Flows
(MLD)
I Ukkadam 70 24-30 MLD Sequential Batch Reactor (SBR)
II Ondipudur 60 - SBR
III Nanjundapura 40 - SBR
Total 170 24-30 MLD

City’s Vision for Sanitation: The CCMC is committed to ensuring universal access to toilets. CCMC
constructed 58 public / community toilets under SBM-U, which along with construction of 4,862
IHHLs, has resulted in the city being declared ODF in December 2017.

The CCMC is also committed to providing safe collection and disposal systems for waste water
generated in the city. To meet this objective CCMC has adopted a three pronged approach including
a) implementation of UGSS in uncovered areas (of erstwhile CCMC and newly incorporated areas); b)
septage management / decentralised treatment for uncovered areas; and c) assessing feasibility for
reuse of waste water.

The ongoing UGSS project18 covers an area of 105 km2 (corresponding to the area of erstwhile
CCMC) with laying of sewer lines along 582.88 km19 and 103,506 household connections. In addition,
a Detailed Project Report (DPR) has been prepared for covering the recently added areas (152 km2)
with UGSS. This project is estimated to cost INR 16,310 million and CCMC is exploring funding for the
same. Further, a feasibility study for implementing a Tertiary Treatment / Reverse Osmosis facility
for reuse and recycling of domestic sewage is also under consideration.

B. Co-treatment – Genesis
Coimbatore initiated co-treatment of septage at Ukkadam STP in 2011, soon after the plant was
commissioned in January 2011. The main driver for initiating co-treatment was the fact that majority
of the households in the city were connected to on-site sanitation systems and private operators
involved in desludging septic tanks were rampantly dumping septage into the city’s open areas and

15 The works at Ondipudur STP were completed in April 2014. However, the plant hasn’t been commissioned as yet as work for the
collection system and household connections has not been completed as yet.
16 The work at Nanjudapuram STP has been held up since April 28, 2009 due to public litigation. Consent to establish was obtained

by the CCMC from the Tamil Nadu Pollution Control Board (TNPCB) on October 25, 2012. The subject was approved by the city
council on March 18, 2013 and forwarded to CMA for getting approval. Meanwhile on April 2, 2013 the National Green Tribunal
(NGT), South Zone ordered all work to stop. The argument of the case was concluded in its 9th hearing on January 23, 2014 and the
case was dismissed. The judgement was delivered by NGT South Zone on April 24, 2017 and the CCMC was asked to resume work
at the STP. Officials at CCMC shared that the process of preparing the revised cost estimates is currently underway.
17 Source: CMWSSB
18 For which funding was available under JNNURM
19 This includes laying sewer lines along 582.88 km and work has been completed for 572.40 km

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 Ukkadam STP, Coimbatore, Tamil Nadu

water bodies. The CCMC wanted to put an end to the unauthorised dumping of septage and the
resultant pollution of the city’s open areas and water bodies.

The Government of Tamil Nadu in its “Operative Guidelines for Septage Management for Urban and
Rural Local Bodies, 2014” (hereafter referred to as Operative Guidelines) has identified STPs in
Coimbatore to serve as a regional facility for treating septage of six Town Panchayats20 and four
Panchayat Unions21 located in its vicinity. However, discussions with CCMC officials revealed that the
co-treatment facility at Ukkadam is available only to private desludging operators operating within
the area under the jurisdiction of CCMC (i.e., 257.04 km2). The private desludging operators are
required to sign an undertaking with CCMC pledging that they will operate only within the area
under the jurisdiction of CCMC and if they are found operating outside, their contract is terminated.

When co-treatment was initiated at Ukkadam in 2011 only 25 private desludging trucks were
registered with CCMC22. Simultaneous to the initiation of co-treatment facility at Ukkadam, the
CCMC undertook drives for enforcement of the environmental protection and pollution control laws.
Fines (challans), ranging from INR 25,000 to INR 50,000, were imposed by CCMC on desludging
trucks found dumping septage in the open environment. In addition, the truck was impounded
which was a double blow to the operators as they could not do any business until their vehicle was
released. This measure is seen to be the main reason for a steady increase in the number of trucks
registered with CCMC. At present, 65 trucks are registered with CCMC, varying in capacity from 3m3
– 8m3. The officials were of the opinion that all private desludging trucks operating within the
jurisdiction of CCMC have been registered.

Contractual arrangements with private desludging operators: As per the Operative Guidelines only
certified and licensed septage transporters are authorised to desludge and transport septage to the
STP designated for co-treatment. In line with these provisions, all private desludging operators
operating in Coimbatore have to register with CCMC after signing a formal agreement. The
agreement applies to a single truck, while some operators have more than one truck. The agreement
is required to be renewed annually. As a part of this agreement private desludging operators pledge
to follow the rules (Table 2) set out by CCMC for co-treatment.

Table 2: List of Rules set by CCMC for private desludging operators partnering in co-treatment at Ukkadam
1 The private desludging operators will discharge the collected septage only at Ukkadam STP and not in
the open areas, drains or water bodies anywhere within or outside the city
2 The private desludging operators will not discharge any industrial waste / effluent at the STP
3 The private desludging operators will use the facility only between 6 am and 6 pm
4 The private desludging operators will maintain a queue at the decanting point
5 The private desludging operators will maintain a log of their entry at the decanting point
6 The private desludging operators will paint a large (easy to read) display on their trucks indicating that
the truck has been licensed by the CCMC
7 The private desludging operators are required to pay a tipping fee of INR 1,500 per month per truck,
to be paid in advance as a quarterly fee of INR 4500
8 The private desludging operators will ensure that the following safety equipment is available on the
vehicle and is used by the driver and helper: Gloves 410, Orange jacket 2”, Mask Venus V 90 with clip,
Safety belt, Helmet, Gumboot, Goggle #M 1621, LED Head Torch, Light and Mask 2m 1200
9 The private desludging operators will get the staff (both driver and helper) insured (INR 10 lakhs per
person)

As an annexure to the agreement the operators are required to submit various documents (Table 3)
for every truck.

20 Including Sakar Samakulam, Vedapatty, Perur, Vellalur and Inugur

21 Periyanaickenpalayam, Sarkarsamakulam, Thodamuthur and Sulur
22 Source: CCMC

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 Ukkadam STP, Coimbatore, Tamil Nadu

Table 3: List of documents to be submitted by private operators while entering into an agreement with
CCMC
1 Registration Certificate (RC) from the Regional Transport Office (RTO)
2 Permit issued as a Medium Goods Vehicle (Form 38) complying with the provisions of Section 56 of the
Motor Vehicles Act
3 Dangerous and Offensive (D&O) Trades License (which is issued by CCMC)
4 Pollution Under Control (PUC) Certificate
5 Insurance documents of the vehicle
6 Driver’s driving license
7 Certificate that the vehicle has installed an electronic speed limit system
8 Bill as proof of purchase of mandatory safety equipment (including Gloves 410, Orange jacket 2”, Mask
Venus V 90 with clip, Safety belt, Helmet, Gumboot, Goggle #M 1621, LED Head Torch, Light and Mask 2m
1200
9 Documents of personal insurance policies for both the driver and helper (value of INR 10 lakhs per
person)

While there is no registration charge or

annual fee, the operators have to pay INR
1,500 as tipping fee per month per truck. This
is to be paid in advance on a quarterly basis,
amounting to INR 4,500 per quarter.

Private desludging operators come together:

The private desludging operators have come
together in the form of an association, called
the “Septage Lorry Association”. All private
desludging operators who are registered with
CCMC are members of this association.
Regular meetings are held with CCMC which
serve as a medium for operators to share
Truck displaying a sign that it is registered with CCMC
their problems and seek interventions
towards their resolution from CCMC.

The formation of the association has enabled operators to negotiate with CCMC regarding the
tipping fee. CCMC officials shared that in late 2017 they had proposed raising the tipping fee from
INR 1,500 per month to INR 2,500 per month per truck but this move was vehemently opposed by
the association citing reasons such as traffic congestion in the city, increase in diesel prices, increase
in labour cost, increase in vehicle maintenance costs and their inability to increase the fee for
desludging and transporting septage from households23. The result was that the tipping fee wasn’t
increased.

C. Co-Treatment at Ukkadam STP

Plant Background
Ukkadam STP is located in the western part of the city and serves an area of approximately 23 km2
which is covered with UGSS. The STP is based on “Sequential Batch Reactor” (SBR) technology. The
plant has a capacity of 70 MLD while the wastewater flow ranges from 25 to 30 MLD. The presence
of spare treatment capacity (of 40 to 45 MLD) enabled implementation of co-treatment of septage
at Ukkadam STP.

23 At present they charge households a fee ranging from INR 800 to 1000 per trip

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 Ukkadam STP, Coimbatore, Tamil Nadu

Half of the treated waste water from Ukkadam STP is supplied (through a pipeline) to the city’s Golf
Club; the remaining is discharged into Noyyal River. There is neither any charge levied nor any
formal agreement for supply of treated wastewater (with water quality specifications) to the Golf
Club. The dried sludge (approx. 300-500 kg per month) is given free of charge to the Forest College.
For details on the Ukkadam STP refer Annex 3.

Planning and Implementation of Septage Co-treatment

Co-treatment of septage at Ukkadam STP was initiated in early 2011. The un-sewered areas of the
erstwhile CCMC (82.06 km2) and the recently added areas (152 km2) are served by the co-treatment
facility at Ukkadam. Private operators are involved in desludging septic tanks and they charge
households a fee, which ranges from INR 800 to 1,000 per trip.

Sixty five private desludging trucks, with capacity ranging from 3 kL to 8 kL are registered with the
CCMC for discharging septage at Ukkadam STP. Each truck makes multiple (2 – 3) trips every day and
about 13024 19525 truckloads of septage are discharged at Ukkadam on a daily basis. Septage
decanting is permitted at only one location in the city, which is an uncovered drain (Nalla) located
about 500 meters from the STP.

Volume and Quality of Septage

The facility receives about ~16026 truckloads of septage on a daily basis or about 0.88 MLD27 of
septage which is blended with ~30 MLD of sewage (therefore septage is ~ 3 percent of the current
sewage flows). Due to absence of data, comparison of characteristics of raw sewage and septage is
not possible. The city does not undertake quality testing of septage prior to its addition to the raw
sewage at the decanting point.

Infrastructure Investments and Operational Changes for Co-treatment

Decanting Station: While the Operative Guidelines issued by GoTN have made it mandatory for STPs
undertaking co-treatment to create a dedicated decanting station, there is no such infrastructure
which has been created at Ukkadam.

The decanting site is an open drain (nalla), located about 500 meters upstream of the STP, which
carries sewage to the plant. The decanting point does not have a boundary wall or even a fence. The
access to the site is through a dirt path which is not paved or cemented, and the result is that every
time a truck drives in / out a thin envelope of dust is created. There is enough space for three trucks
to decant septage simultaneously.

While the trucks are permitted entry between 6 am and 6 pm every day, there is no mechanism to
control the entry of trucks. Neither does the decanting point have a boundary wall nor is there any
supervisor to monitor the entry and exit of trucks. CCMC plans to construct a security room
(dimensions 10’ x 10’) and a store room (dimensions 20’ x 10’) at the decanting site to enable
recording the movement of trucks and to store safety equipment. The CCMC has made a provision of
INR 2 million in the budget for FY 2018-19 for the same.

The trucks usually have a driver and a helper on board. The truck arrives and parks at the decanting
point following which the helper connects a pipe through which the septage is discharged into the
open drain. The entire process takes around five to ten minutes.

24 Assuming 2 trips are made by every truck each day

25 Assuming 3 trips are made by every truck each day
26 Average figure, arrived after adding the total trips assumed at 2 trips per truck (130) and three trips per day (195) per day
27 Calculated at 160 truckloads with an average capacity of 5.5 KL (average of 3-8 KL)

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 Ukkadam STP, Coimbatore, Tamil Nadu

Staff connecting the pipe to the truck View of the pipe and the open drain into which
septage is decanted

Truck decanting septage Trucks parked at the decanting site

Retrofits or additions to the treatment process: Discussions with staff at the STP revealed that there
have been no retrofits or additions required to the treatment process after mixing of septage with
sewage prior to treatment.

Sampling and Monitoring Protocols: While the Operative Guidelines require regular testing of input
quality of septage in order to identify metals or traces of industrial waste, testing of septage is not
being undertaken at present at Ukkadam.

Record Keeping Protocols: As per the Operative Guidelines, a supervisor should be appointed at the
decanting station / point but no staff has been positioned at the decanting point in Ukkadam. There
are thus no records available on the number of trucks using the facility. In the absence of a
supervisor the private desludging truckers are expected to maintain a log of their visits to the STP in
a log book given to them by CCMC.

Safety protocols: As per the agreement with CCMC, private desludging operators are supposed to
ensure that the following safety equipment is available on the vehicle and is used by the driver and
helper – gloves 410, orange jacket 2”, Mask Venus V 90 with clip, Safety belt, Helmet, Gumboot,
Goggle #M 1621, Led Head Torch, Light and Mask 2m 1200. During our visit, we did not find staff
using any protective gear apart from the orange jacket.

Financial Details
Capital Cost: No additional retrofits or modifications requiring capital investment have been made at
the STP to enable co-treatment. CCMC plans to construct a security room (dimensions 10’ x 10’) and
a store room (dimensions 20’ x 10’) at the decanting site to enable recording the movement of

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 Ukkadam STP, Coimbatore, Tamil Nadu

trucks and to store safety equipment. The CCMC has made a provision of INR 2 million in the budget
for FY 2018-19 for the same.

O&M Cost: A comparison of the O&M cost prior and post co-treatment isn’t possible as co-
treatment was initiated immediately after the plant was commissioned in 2011.

Tipping Fee: Fee of INR 1500 is charged per truck per month (irrespective of the number of trips
made) for disposal of septage at Ukkadam. As mentioned earlier, this tipping fee is to be paid in
advance per quarter amounting to INR 4,500. The tipping fee collections are approximately INR 1.17
million per annum28. (Table 4)

Table 4: Charges for co-treatment – Tipping Fee

Type of charge Frequency Rate (in INR) Total collection in INR
(approximate)
Tipping fee Per truck per month INR 1500 1.17 million per year

Performance Details
Total Suspended Solids (TSS): As per design parameters of Ukkadam STP, TSS in raw sewage should
be between 200 to 400 mg/l. In some months (July 2016; March, April and May 2017) the inlet TSS
figures are over 400 mg/l. The treated effluent has TSS figures well within the prescribed level i.e.,
under 10 mg/l during most of the year except in the months of May and June 2017. (Figure 2)

1000 100
448 438 434 444
252 272 252
180

18 18
100
12
10
8 8
10
6
4
10
2

1 1
14.07.2016 24.11.16 24.03.17 12.04.17 19.05.17 27.06.17 21.07.17 21.04.2018

Inlet Effluent Prescribed

Figure 2: TSS levels (inlet and effluent)

mg/l

28 Based on 65 trucks paying tipping fee of INR 1500 / truck per month.

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 Ukkadam STP, Coimbatore, Tamil Nadu

BOD: The prescribed levels of BOD in raw sewage (as per the plant’s design parameters) should be
between 200-400 mg/l. In March 2017 the inlet BOD figure was found to be over 400 mg/l. The
treated wastewater has BOD well within range of applicable standards of < 10 mg/l in all months
except June 2017. (Figure 3)

1000 100
460 400
234
160
128 120
90
100 66
11
8
7 10 10
6
5 5
4
10 3

1 1
14.07.2016 24.11.16 24.03.17 12.04.17 19.05.17 27.06.17 21.07.17 21.04.2018

Inlet Effluent Prescribed Level

Figure 3: BOD levels (inlet and effluent) mg/l

D. Impact of Co-treatment
City population being served by co-treatment: The initiative has been successful in serving the un-
sewered parts of the CCMC. Given that there are approximately 160 trips per day to the Ukkadam
STP, it is estimated that the co-treatment facility is able to provide septage treatment solution for
between 1.35 to 2.4 Lakh households with septic tanks per year29.

Regularisation of private desludging operators: The 65 private trucks that are registered with the
Ukkadam STP have been provided with a safe and economical option for discharging septage.

Environmental Impact: The initiative has ensured that unauthorised dumping of septage in the city’s
open areas and water bodies has reduced substantially.

Source of Revenue for the STP: The user charges collected from private desludging operators /
trucks is resulting in generating revenue to the tune of about INR 1.17 million per annum.

E. Key lessons and practices

• The sound policy framework put in place by the GoTN in the form of the “Operative
Guidelines for Septage Management for Urban and Rural Local Bodies” has laid out the
broad contours for co-treatment in the state. While the CCMC has made a provision for co-
treatment of septage at Ukkadam, it needs to do a lot more to ensure that it adopts the
recommendations of the operative guidelines in their true spirit for safe decanting and
conveyance of septage to the STP. This would include expanding the service of co-treatment
to the surrounding urban and peri urban settlements; creating a decanting station; putting in
place record keeping, testing of septage and safety protocols.

29Estimated based on number of households that can be serviced when septic tank sizes varies from 4 to 10 m3 and when
desludging is done once every 3 or 5 years.

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 Ukkadam STP, Coimbatore, Tamil Nadu

• The fact that the CCMC undertook rigorous enforcement of environmental protection and
pollution control provisions in tandem with initiation of co-treatment has proved critical to
move private desludging operators towards a regulated regime and dissuade illegal dumping
of septage.
• The STP at Ukkadam receives a very small amount of septage (about 3 percent by volume of
the current flows received at the STP). Data on treated wastewater available for a few
months in 2016 and 2017 indicates that there are no significant impacts on the final effluent
quality. It seems that the plant is able to handle and treat the additional load from septage
without impacting unit operations.
• Record Keeping Protocol needs to be put in place to control and record the movement of
trucks in and out of the decanting point.
• Safety protocol needs to be put in place to identify and eliminate industrial waste from
being disposed of at co-treatment facilities; this must include random testing of the septage
being decanted at the STP.
• Given the large amount of spare capacity at this STP and the success achieved in septage co-
treatment, CMC could allow disposal of septage from neighbouring towns and village at this
STP. The collaboration between urban and rural areas will not only help in greater amount of
septage being co-treated scientifically and safely, but will also add to the revenues of CMC
from additional tipping fee.

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 Ukkadam STP, Coimbatore, Tamil Nadu

Annex I: Coimbatore – Population (Census 2011)

A Erstwhile CMC 1073020
B Municipalities added in 2011 379130
Kavundampalayam 98919
Kurichi 159523
Kuniamuthur 120688
C Town panchayats (TP) 151561
Chinnavedampatti TP 13177
Kalapatti TP 26441
Saravanampatti TP 21284
Vellakinar TP 11726
Thudiyalur TP 25205
Vadavalli TP 29735
Veerakeralam TP 23993
D Village panchayat 14000
Vilankurichi village panchayat 14000
Total 1617711

City map of Coimbatore – Zones

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 Ukkadam STP, Coimbatore, Tamil Nadu

Annex 2: Status of access and collection and conveyance systems in

Coimbatore
Table 1: Access to toilet facilities (Census 2011)
Access to Sanitation Facilities Number of households %
Individual Toilets 248,332 87.80
Public Toilets 27,435 9.70
Open defecation 7,072 2.50
Total households 282,839 100.00

Table 2: Collection and Conveyance systems (Census 2011)

Number of households %
Piped sewer 91,639 36.90
Septic Tank 140,570 56.61
Other Flush System 848 0.34
Pit with slab / VIP 12,162 4.90
Without slab/ open pit 565 0.23
Night soil disposed into open drain 1,697 0.68
Night soil serviced by human 565 0.23
Night soil serviced by animal 282 0.11
Total 248,328 100.00

4.90% 0.23% 0.68% 0.23% 0.11%

Piped Sewer
0.34%
Septic tank
36.90% Other flush systems
Pit with slab / VIP
Pit without slab / open pit
56.61%
Night soil disposed in open drain
Night soild removed by humans

Collection and conveyance mechanism for septage in Coimbatore, Census 2011

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 Ukkadam STP, Coimbatore, Tamil Nadu

Annex 3: Details of Ukkadam STP

Design Capacity 70 MLD
Waste water Flows / 20-30 MLD
Average quantity treated
Treatment Technology Sequential Batch Reactor (SBR)
The treatment facility at Ukkadam consists of screen chamber (coarse screen and
fine screen), grit chamber, settling tank, sludge digestion tank and sludge drying
bed.
A typical cycle lasts 4 hours (including 2 hours for filling and aeration, 1 hour for
settling and 1 hour for decanting). Six such cycles are run every day. The plant has
8 blowers (capacity of 210 HP ) of which ¾ are working at a time. Chlorination is
the form for tertiary treatment
Year of commissioning January 2011
Project under which JNNURM
construction was funded
Cost (In INR) 550 million
Number of Pumping DNA
stations
Areas covered 23 km2
Area of the STP DNA
O&M responsibility Outsourced (M/S Gharebure Engineering Constructions, Pune)
Repair and Maintenance Outsourced (M/S Gharebure Engineering Constructions, Pune)
Duration of the contract 6.5 years (including 6 months trial run, 1 year performance run and 5 year O&M
contract)
Contract Value INR 70 million
Payment per month DNA
Treatment cost per ML DNA
Discharge Point River Noyyal (50%)
Golf Course (50%)
Use of sludge The dried sludge is given free of charge to the Forest College (approx. 300-500 kg
per month)

Design Parameters - Raw sewage and effluent characteristics
Parameter Unit Raw Sewage (value) Effluent (Value)
A BOD5 @20 degree C mg/l 200-300 10 or less
B COD mg/l 400-500 Less than equal to 100
C Total Suspended Solids mg/l 200-400 10 or less
D Kjeldahl Nitrogen mg/l 15 Less than equal to 10
E Ammonia Nitrogen mg/l 10 Less than equal to 2
F Total Phosphorus mg/l 5 Less than equal to 2
G Faecal coliform No./100 ml 106 Less than equal to 200
H Total coliform No./100 ml 107 Less than equal to 500
I PH 7-9 7-9
E Oil and grease mg/l 15 Less than equal to 5

O&M Costs at the Ukkadam STP
1 Labour cost 5.83 million
2 Chemicals and consumables 2.84 million
3 Civil works 3.83 million
4 Mechanical and Electrical works 8.89 million
Total 21.34 million

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 Ukkadam STP, Coimbatore, Tamil Nadu

Annex 4: List of officials met at Coimbatore

S. Name, designation, Mobile Email
No. organisation
1. Mr. A Lakshmanan 9443799211 cityengineer.coimbatore@gmail.com
City Engineer, CCMC
2. Mr. Santosh Kumar 9443799202 -
City Health Officer 9444481398
3. Ms. Parvathy 9443799243 -
Engineer on deputation, CCMC
4. Mr. R. Maniraj 9698698719 maniraj4all@gmail.com
Staff, Ukkadam STP
5. Mr. Karthik 9442501873
Assistant Programmer, CCMC

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