Tele: 23018523

86435/Misc/s2_,/E4 (U3) v, Apr 2020

ENGINEER- IN- CHIEF'S BRANCH Sub-Dte of Utility (E-41

UPLOADING OF PHE POLICIES AND ESTIMATING DATA-2016 EIM & PHE

1 It is seen that on MES website, mes.gov.in ,the following policies of PHE not

available for users- 2017 (a) E-in-C Branch letter No 86435/Misc/E4(U3) dated 19 May

(b) Estimating data -2016( E/M & PHE Work)

2 The policies referred above are decisive for planning and designing of PHE

schemes

3. It is requested to upload the policies for dissemination of the same.

v't (K VCi ayaka) Lt C SO-1 E-4 (U3)

Automation Cell

Enclosures: As above

Tel : 011 23015303 Fax : 011 23019113

86435/Misc/E4(U3)

Sub Dte of Utility (E4) Dte of Works,

Engineer-in-Chief's Branch Kashmir House, Rajaji Marg

New Delhi 110011

Ict May 2017

E-in-C List 'A' & 'B'

Guidelines for Planning and Design of Sewer Networks and STPs

1. On perusal of DPRs for PHE schemes submitted by various zones it is analysed that there is a need to issue guidelines on certain design and planning aspects so as to facilitate faster clearances of PHE projects by this HQ. The consultants hired by Chief Engineers are mostly having experience of working in normal city like conditions and they tend to ignore the peculiarities in Defence establishments in their DPRs.

2. Low population densities, fluctuating populations, high sanitation standards, remote locations, large unpaved areas, stringent discharge requirements and extreme climatic conditions make planning of PHE schemes a challenge for MES planners and designers.

3. List of issues which get neglected by consultants has been prepared and the same is discussed in subsequent paragraphs. Suggestions to include these issues in our schemes have also been given so that in future schemes, these issues are adequately addressed.

(a) Ground Data Required. Ground data required for planning of PHE schemes is reproduced at appendix 'A' to this letter. It is important to note that every data required has relevance in the process of planning or design.

(b) Calculation of quantity of sewage. Scale of Accommodation Appendix 'C' must be used for working out water requirement and subsequently to calculate the sewage generated. Ingress of ground water must be added as per site conditions and in accordance with Manual on sewerage and sewage treatment systems (Manual). It is important to note that if DWCPE sewers are to be used the ingress of ground water should be assumed on lower side while with RCC NP3 sewers it should be of mid-range. In either case total ingress should be less than 10% of sewage generated.

(c) Storm Runoff. In MES central sewage sewers are not designed to carry storm runoff. Open road side drains are provided for storm waters and are therefore designed separately.

(d) Layout Plans and Contours. Consultants tend to ignore importance of contours and layout plans for planning of network of sewers. Preferably layout plans should be prepared on scale so that entire station is easily covered in one Ao drawing. In addition zoomed up detailed plans at scales 1: 1000 on A3 sheets may be prepared along with key plans for ease of understanding and readability. Contours, existing networks, water supply lines, underground cables and other services should be marked. Details of existing sewers including size of sewers, load and invert level are essentially required for synchronization with new schemes. Colour schemes in line plans should facilitate easy understanding and reading. Alternately SP-46 of Bureau of Indian Standards may be followed for preparation of engineering drawings.

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(e) Higher Peak Factor for discharges. Hitherto, in MES a peak factor of 4 is being used for population up-to 25,000. However, for very small populations say up-to 500 peak factor of 4 is unrealistic. Literature survey on internet was done and reference by IIT Kharagpur was found where IIT in their web courses have recommended peak factor of 6 for small populations. It appears to be realistic keeping in view the fact that large variation in discharges are observed for very small population in MES also. Therefore, for very small populations peak factor of 6 is recommended in MES for population up-to 500. It will result in substantial saving in cost of excavation for laying of sewers.

(f) Automatic Flushing Tanks(AFT). AFTs are provided to generate self-cleansing velocity in gravity sewers however, these are difficult to maintain and requirement of additional water supply makes them undesirable. Therefore, use of AFT is proposed to be restricted only for very small populations. Alternately treated sewage through dedicated pressure lines be used for flushing of sewers. However, precautions to avoid cross connections of these lines must be ensured thus control valves should have detachable spindles and all pipes/fixtures should be of violet colours.

(g) Specifications for Hot Climates. In case of hot climates the self-cleansing velocity should be taken as 0.8 m/s instead of 0.6 m/s to minimize formation of slimes and H2S gas in sewers. For this purpose a station having average daily temperature more than 30° C for at least three months may be defined as hot climate.

(h) Specifications for Extreme cold climates. For extremely cold climates the insulation of sewers and STP is vital. ED 2016 caters for additional cost of these measures @ 8% increase per 5° C fall in average ambient temperature for more than three months below 20° C is allowed.

(.1) Technologies of STPs in MES. In MES MBBR has been accepted as standard technology for STPs of 100 KLD capacity and more. However, there is no embargo in use of other cost effective technologies having matching foot prints, which are approved by various central government agencies. In such cases performance assurance for complete life cycle of STP should be obtained and there should not be any exclusive dependence on OEM, for chemicals or Biomass, after 5 years of M&O.

(k) Decentralized sewage systems. These days, decentralized sewage systems are being preferred as cost of transport of sewage and that of treated effluent is reduced. In MES since the size of STPs is generally much small in comparison to civil setups, therefore it may not be economical to use decentralized plants in every case. Therefore, Zonal CEs should ask consultants for planning different options in totality including cost of transportation of sewage and that of treated effluent for reuse. Cost-benefit analysis for all options should be done by consultant to facilitate Zone to select most efficient system.

(I) Reuse and final disposal of treated effluent. Unless there are compelling reasons, reuse of sewage will be done to reduce demand of fresh water. Various possible non-potable applications treated effluent are i.e. arboriculture, irrigation, fire fighting, washing of pavement/roads, flushing of toilets, construction activities and development of water bodies. To avoid accidental cross connections with fresh water lines, measures as mentioned in para (f) ante are to be ensured. Parameters for disposal and reuse will be in accordance with State Bye-laws, however, suggested values are given at Appendix 13' to this letter. These days some SPCBs have made stringent standards for disposal and have started asking for zero discharge concepts. In such situations, it will be appropriate to have a water body of not more

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q/r

than 2.0m depth in the station where treated effluent can be stored. The percolation and evaporation from water bodies can be designed as final disposal. These water bodies can also act as storage tanks for other reuses. To avoid reappearance of bio mass, fountains/ cascades must be provided.

(m) Vetting of DPRs. It has been observed that DPRs prepared by consultants are not scrutinised by many zonal CEs and consultants are directed to this HQs for clearance of DPRs. Vetting of DPRs by engineering colleges is not done seriously as there is no involvement of department causing delays due to inflated or technically unsound reports. This practice is not correct. Henceforth following procedure may be adopted.

(i) Consultant submits DPR with various proposals to Zonal CE. (ii) CE gets validation of ground data by concerned GE. (iii) Proposals are examined at zonal level for feasibility on ground. (iv) One proposal be selected for execution. (Please refer para 'k' ante). (v) Selected proposal be got technically vetted by consultant from IIT/ NIT/ ADG

(D&C) /Nominated PHE expert of Comd or E-in-C's Br. (vi) Revised DPR duly incorporating the suggestions of vetting agency to be

submitted by consultant. (vii) Such schemes once vetted by I IT/NIT/ADG(D&C) or PHE expert will not require

technical check at E-in-C's Branch, however, financial vetting as per practice in vogue will continue.

(n) Accountability of OEM. OEM or vendor will not be accountable for hydraulic design aspects of STP if design is done by consultant or department unless during tendering process suggestions of OEM or vendors on design related issues have been incorporated in 'Q' bid. Services of consultant may be continued during execution stage also to ensure implementation of workable STP to have sound technical decisions on any unforeseen issue. A clause to this effect should be included in tender to avoid unnecessary litigation at a later date.

4. Please ensure that above guidelines are followed for all PHE schemes.

5. This has approval of DGW.

(S K Arora) Dir (PHE)

For E-in-C

Copy to :-

DG MAP ADG(D&C) Pune Jt DGW (Contracts) DDG PPC DDG Design

'.)ytteji/Y1-52-e

P1-1)94-t

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Appendix 'A' to Sub Dte of Utility, DG(Wks), E-in-C's Br letter No 86435/Misc/E4(U3) dated 19 May 2017

LIST OF DATA REQUIRED FOR PLANNING AND DESIGN OF STP SCHEMES

1. Ground Data a. Layout plan of Station with existing network of sewers.

b. Contours at 0.5 m interval superimposed on layout plan. Contours should be linked to

nearest Survey of India permanent bench mark.

c. Location of all present and proposed buildings with sewage load.

d. Proposed location of STP and reuse of treated wastewater.

e. Location, Depth and NOC regarding use of Municipal sewer.

f. Plans showing water distribution network, under cables and other UG services.

g. Depth of water table and Soil characteristics including SBC up to 10 m depth or till hard

strata is achieved at a grid of 500 sm with at least one point at location of STP.

h. Seismic zone of region.

i. Highest intensity of rainfall and HFL for 50 years at STP site.

2. Raw Sewage Characteristics The best way to ascertain the sewage characteristics is to conduct the composite

sampling once in a week for diurnal variation on hourly basis from the existing sewage outfall.

Considering four week month, three samples are to be taken on weekdays and the fourth

sample on off day i.e. Sunday. Sampling should be done for at least one month during lean

flow season. Parameters to be tested are listed below.

In the absence of actual sewage outfall the parameters to be assumed are mentioned

at table below. However, design should be re-verified once actual data is available.

RAW SEWAGE CHARACTERISTICS IN ABSENCE OF ACTUAL DATA

SN Parameter Value Remarks

1 BOD 200 mg/L For hot climates = 300 mg/L

2 COD 350 mg/L For hot climates = 450 mg/L

3 SS (Total) 250 - 300 mg/L

4 Nitrogen (Total) 50 mg/I

5 Phosphorus (Total) 7.0 mg/I

6 Temperature ambient

7 Coliforms (Faecal) 105-106/ 100 ml

8 Oil & Grease 20 - 30 mg/I (for EME work shop > 50 mg/I)

9 Chlorides & Sulphates As per water sample.

10 Heavy Metals Only if industrial contamination is expected.

11 pH 6.5 — 8.5

12 Colour and Odour Actual I A. /4

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Appendix 'B' to Sub Dte of Utility, DG (Wks), E-in-C's Br letter No 86435/Misc/E4(U3) dated 19 May 2017

PARAMETERS FOR VARIOUS REUSE OF TREATED SEWAGE SN Parameter (2) Unit (3) Arboricultur

e/ Golf course, (4)

Irrigation for non- edible crops (5)

Toilet Flushing (6)

Fire Fighting (7)

Eco lakes (8)

Construction Activity (9)

1 pH 6.5 — 8.3 6.5 — 8.3 6.5 — 8.3 6.5 — 8.3 6.5 — 8.3 6.5 — 8.5

2 TDS mg/I 2100 2100 2100 2100 2100 < 3000

3 Turbidity NTU <2 As arising <2 <2 <2 Please refer para 5.4 of BIS 456.

4 TSS mg/I < 10 30 < 10 < 10 < 10

5 Temperature 0C Ambient Ambient Ambient Ambient Ambient

6 Oil & Grease mg/I 10 10 10 Nil nil

7 Res. Chlorine mg/I > 1 Nil > 1 > 1 > 0.5

8 Total Kjeldhal Nitrogen mg/I 10 10 10 10 10

9 BOD mg/I 10 20 10 10 10

10 COD mg/I As arising 30 As arising As arising As arising

11 Dissolved Phosphorous mg/I 2 5 1 1 1

12 Nitrate Nitrogen as N mg/I 10 10 10 10 5

13 Faecal Coliform

MPN/ 100 ml nil 230 nil Nil nil

14 Helminthic Eggs count/I As arising <1 As arising As arising As arising

15 Colour Colourless As arising Colourless Colourless Colourless

16 Odour No foul odour

No foul odour

No foul odour

No foul odour

No foul odour

17 Helminth Egg <=1 egg/L As arising <=1 egg/L <=1 egg/L <=1 egg/L

18 Sulphates mg/L As arising As arising As arising As arising As arising < 400

19 Chlorides mg/L As arising As arising As arising As arising As arising < 500

20 Acidity mg/L As arising As arising As arising As arising As arising < 50 mg/L

Type of final treatment normally required. (Actual treatment may vary as per site condition)

Tertiary treatment

Secondary treatment + Filtration + Disinfection

Tertiary + Ultra Filtration

Tertiary treatment

AAA/

Tertiary + continuous aeration.

Tertiary treatment

It

qr5 5 Col Rajat Baijal

Digitally signed by Col Rajat Baijal DN: c=IN, st=Kashmir, o=E-IN-C' Branch Army MOD Room No - 160 Automation Cell EINC Branc, ou=nonnic-mail-admin, cn=Col Rajat Baijal, email=autocell-einc-army@nic.in Date: 2017.05.26 15:49:24 +05'30'