CONSULTANCY SERVICES FOR PREPARATION OF DPR FOR PROVISION OF TWO Nos STP IN TECH AND DOMESTIC AREA AT AFS THANJAVUR

Amount

Design of one STP at domestic area and one STP at Technical area at Air Force Station Thanjavur including topography survey, soil investigation, preparation of drawings, complete estimation of the project duly vetted by IIT/NIT or Govt. Engineering college complete. The detailed scope of consultancy work will be done in three phases.

(c) Quantitative assessment of raw waste water / sewage for average & peak load: i. The sewage load shall be determined based on the actual population and water availability and consumption of the station. ii. The strength of Pers in AF Stn shall be based on sample survey conducted in consultation with GE. The sewage load shall be estimated based on such sample survey. iii. If feasible, the quantity of sewage shall be measured using flow meters for determining sewage load. iv. Water table data especially during high flood levels during peak monsoon levels shall also be included in the report. v. Sewage load to be calculated Area / Pocket wise for planning & designing the sewer network. (d) Qualitative assessment of sewage from different pockets of area shall be got done from NABL approved Lab. Consultant shall pay necessary fees and expenditure for the same. The parameters for raw sewage shall be determined using grab samples from the exiting sewage outfalls from different pockets of area. The sampling shall be done once in a week for diurnal variation on hourly basis. Considering four week month, 03 Nos of samples are to be taken on weekdays and fourth sample on off day i.e. Sunday. Sampling should be done for at least one month during lean flow season. (e) Review the health of existing sewer network, existing and Sewage treatment scheme/units. The adequacy of exiting sewage disposal scheme wrt to sewage load shall also be checked. The defects/malfunctions in the existing Sewer lines and sewage treatment scheme/units shall be brought out in report. (f) Consultant shall give details of repair methodology of existing sewage network and scheme or replacement/augmentation of Sewage disposal scheme. Details of repair involved in terms of items/quantities(BOQ) to revive the existing sewage disposal scheme shall be provided. If replacement of scheme is recommended, detailed cost of replacement with items/quantities in BOQ shall be provided.

(l) Based on the Report of Phase-I, CE Zone shall choose the option for providing most efficient sewage disposal scheme. The final option shall be given in writing to the Consultant and Phase-II of the consultancy shall be activated accordingly.

II. Work under Phase II will comprise the following scope of work :- (A) Stage -1 : Hydraulic design of Sewerage network, STP, Submission of Draft report and Departmental approval of scheme (i) Hydraulic design of Sewerage network of approved Scheme including addition/alteration/repair/replacement of existing sewer network. Design details shall include design of line sewer, Main sewer and Trunk sewer line wherein dia of pipe from manhole to manhole, depth of pipe, gradient, self cleansing velocity, type of encasing of pipe etc to be given on contour plan on scale of 1:50 and 1:250 depending on the area size. Following points shall be considered in the design; however any change by consultant shall be suitably justified in the report: (ii) Where Self cleansing velocity is not achievable, flushing tanks of suitable capacity to be designed. Flushing tanks shall be restricted to small populations only. Alternately, treated sewage through dedicated pressure lines may be used for flushing sewers. Necessary precautions to avoid cross connections of these lines shall be ensured. (iii) Min depth of sewer lines shall be 1 m, However in exceptional situations initial depth may be reduced up to 0.6 m. wherever depth of sewer is less than 1 m, suitable markers shall be placed along sewer lines. (iv) Min dia of gravity sewer in streets should be 150 mm & for sub-main sewer should be 200mm. SWG pipes shall not be used/considered while designing sewage lines; only NP-3 or DWCPE (SN 8) pipes shall be used.

(v) Self cleansing velocity at 0.6-0.8 m/sec & not exceeding 2.5m/sec to be maintained. (vi) Lift wells to be catered where depth of excavation is more than 6.0 m. Also depth of water table must be ascertained. Sensors shall be used for activation of pumps at lift wells. (vii) Top of manholes to be considered 150 mm above GL. (viii) Minimum slopes of the sewer lines must comply with Table 3.13 of CPHEEO manual (ix) Waste water should not stagnate for more than 25-30 min in wet walls to avoid septic condition. (x) Underground boring to be considered while crossing important main roads to avoid open excavation with trenchless technology. (xi) In case of BC soil, measures to be taken for type & laying of pipes & foundation of other structures. Uplift to be catered in design. Anchored embedment in concrete against uplift be considered. (xii) Bedding of sewer lines to be based on Soil Condition. (xiii) Where Sewer line is less than 1.5 m below the road, they shall be encased in concrete for not less than 15cm. (b) Soil investigation @ 1 borehole minimum at the location of all structures proposed in the scheme to be done as per IS code at the proposed location of various components of STP and @ 500 m c/c along the proposed sewer line. Soil investigation shall be carried out as per details given in Annx-2.

(c) Hydraulic and Structural design of STP units of approved technology. Design of STP including its all components shall include complete Arch design, Structural design, Hydraulic Design, Mechanical design, Electrical control design & circuiting/instrumentation design etc, schematic treatment process, flow diagram with drawings. Design of STP shall comply with guidelines issued by State Pollution Control Board or guidelines issued by Central Pollution Control Board/CPHEEO whichever is more stringent for effluent parameter including management of solid waste / sludge generated out of treatment. Note: i) The provisions contained in IS 4111 (Part 1), IS 4111(Part 2), IS 4111 (Part 3), IS 4111(Part 4), IS 4127, IS 5329, IS 6924, IS 7208, IS 7740 and CPHEEO Manual on Sewerage and Sewage Treatment and on Water supply and Treatment (for recycling of water) shall be strictly adhered to. ii) Structural Design Shall be carried out in compliance to IS 3370, IS 456, IS 1893, IS 13920, IS 875 and IS 6494. Design parameter for structural design is enclosed as Annx-3. iii) Automatic on / off system for pumps & flow measuring devices be incorporated. iv) Pumps to be planned in the manner that one pump for average flow, two pumps for peak flow & one pump as standby is catered (d) Tertiary Treatment : Design of scheme for Reuse of treated water shall also be provided if mandatory by State Pollution Control Board and treated water quality parameters intended for reuse shall be as per SPCB/CPCB/CPHEEO norms whichever is more stringent. Following points also to be considered :

i) If water is recycled, amount of water being recycled and detailed plan for pumping of recycled water to be given ii) Where reuse of treated water is not required / desirable and Tertiary treatment is not planned, suitable disinfection method with type and dosage of chemical to be recommended in report. iii) If treated water after Tertiary treatment is recycled & is being taken inside house for flushing toilets, dual Silver- Copper Ionization for disinfection during Tertiary treatment in synergy with chlorination to be resorted to. Dosage of dual Ionization to be given in report. Consultant shall also give details of distribution system of treated water after Tertiary treatment including separate overhead tanks on buildings, separate pipeline from OH tank to flushing tanks in toilets, etc iv) Re-use : Only tertiary treated water will be recycled. The same after tertiary treatment and super chlorination must satisfy following minimum water quality criteria as stipulated in SPCB/CPCB/CPHEEO norms whichever is more stringent. v) Wherever recycled water is intended to be stored in a covered reservoir sump; the sump will be supplemented with an aeration cascade in any form. The aeration cascade will be capable of circulating entire sump capacity within eight hrs. The preferable time for aeration would remain from 0900-1700 Hrs. (e) Submission of Draft Phase-II Report in 05 Nos. of Hard Copies incl detailed drawings and design calculation, drawings and Hydraulic calculations.

(B) Stage -2 : Vetting of Phase-II report by IIT/NIT On approval of scheme from Department, vetting of Design of Sewerage networks and STP units shall be carried from IITs/NITs/IISc Bangalore. The Sewage disposal scheme along with Hydraulic design/process flow design shall be vetted by Prof with PHE expertise of IITs/NITs/IISc. The structural Design of STP units shall be vetted by Prof of Structural Engineering. The vetting shall be carried on the behalf of the institute and not on individual capacity by the Profs.

(C) Stage -3 : Submission of Phase-II report with BOQ Submission of Duly Vetted Final Report with all design calculation of Scheme, Arch, Structural, Mechanical & Electrical network in 07 Nos. of hard copies including prints of drawings on white sheet and 04 Nos. of Soft copy on CD. (a) All the construction, structural, mechanical, electrical and equipment drawings, working drawing/fabrication drawing duly vetted by NIT/IIT shall be submitted with all dimensions so that it can be executed without any clarification. Detailed drawings to the scale 1:100 on tracing paper duly signed (01 No. of copy) along with Digitally signed DWF drawings on CD (03 No. of copy) shall be submitted. (b) Submission of BOQ against scheme given in Final Report with specification. Items in BOQ with detailed estimates consisting taking off quantities and pricing shall the same on MES SSR Part-II of 2010 & Non-SSR items on market rates separately. Rate analysis of Non-SSR items on market rates shall also be given. (c) Design report & BOQ shall specify at least 2-3 makes for each manufactured items, their specification, names of OEM and quotation. BOQ shall also include O & M cost with details.

III. Work under Phase III will comprise the following scope of work :- (a) Consultant shall render all technical support in between when called for / required during execution of work. (b) The consultancy will be in force till completion of the complete scheme on ground. Execution of work/scheme is not covered in the scope of work.

Scope of work of soil investigation (a) Mobilisation of equipment to site for soil investigation. (b) Labour for making bore hole ( Bore hole-150 mm dia) by any standard method to following depth below ground level in all kinds of soil like clay, silt, sand, stiff clay, mixed silt etc, except rock (for the purpose of collecting disturbed and undisturbed soil samples, conducting standard penetration test at suitable intervals etc). (c) Scope of Soil investigation shall be as follows: (i) Nos of boreholes and depth as decided by consultant. (ii) Open Pit excavation to determine depth and size of fdn of existing nearby bldg as decided by consultant (d) Carrying out the tests to ascertain soil/soft rock profile for determination of Safe Bearing Capacity(SBC) at work site by drilling holes as per relevant/latest IS Code, collecting samples of disturbed and un-disturbed soil. Conducting of following Field and Laboratory investigations, compilation of test results as per relevant and latest IS Codes:- (i) Grain size analysis, identification & Classification of soil.

(ii) Unit weight (bulk density), natural moisture content, liquid limit, plastic limit, shrinkage limit, plasticity index, specific gravity. (iii) Dry density, degree of saturation of soil. (iv) Differential free swell (%) & Swelling Pressure if expensive soil is encountered. (v) Shear Parameters (C-Phi Analysis) (vi) Consolidation test & Permeability test (vii) Chemical analysis of Soil (viii) Chemical analysis of ground water (water to be obtained from bottom of bore hole) (ix) Depth of water table below Ground Level (x) Loose soil/filled up soil, if any and its depth.

(xi) If weak soil with lesser N value as specified in table-1 of IS 1893 (Part-1) 2016 is encountered then evaluation of liquefaction potential shall be assessed and remedial actions to be adopted shall be specified. (xiii) SPT Tests shall be done at 1.5 m interval. (xiv) Crushing strength, degree of weathering (CR value) and RQD of rock samples. (xv) As per IS 1892 clause 3.6.5.3, drilling for 3.0 m depth inside the rock is essential to ensure that boulders or layers of cemented soil are not mistaken for rock. (xvi) For open foundations, Calculation of Net SBC at 1.5m, 2.0m, 2.5m, 3.0m, from shear as well as settlement criteria. SBC value shall be calculated based on C-Phi analysis as well as SPT value. For calculations formula given in IS: 6403 shall be used with shape factor of 1.0. (xvii) If pile foundations are required than depth of piles shall be mentioned and pile capacity in compression, uplift & lateral loads shall be given for 300, 400, 450, 500 dia for under reamed piles & for 450, 500, 550, 600 mm dia for piles as suggested by consultant. (xviii) Recommendations regarding type of foundation to be adopted & Net SBC/ Pile capacities to be adopted. Also recommendations shall be given regarding stability of soil and soil stabilization required, if any. (xix) Borehole positions duly marked on plan and their distance from adjacent prominent reference points. Size of the bldgs shall also be marked in the plan. This plan shall be signed by GE, AGE & Soil consultant. GL of location of Bore holes to be mentioned wrt benchmark and a comparative borelog of all bores shall be made wrt GL of each Borehole.

(xx) Bore log details shall be as per Appx ‘D’ of IS 1892. N values depth wise shall also be shown in details Bore log details shall be signed by AGE, GE & soil consultant. (xxi) Photographs during soil investigation duly signed by AGE, GE and Soil consultant shall be enclosed with soil report. (xxii) Recommendation of CWE & GE regarding SBC & type of fdn to be adopted shall be given in Soil Report.

Preparation and submission of soil investigation report along with Phase-II report. On completion of the complete detailed report the same shall be got verified with HQ CE (AF) Bangalore for obtaining the final approval who being the accepting officer of main STP tender.

SMIT CONSULTING ENGINEERS