Koronadal Water District Tender

Description A. General A. Technical Definitions The Following Definitions Shall Apply: 1. Borehole - Means Any Drilled Section Of Boring Before Completion As Defined In Well Below. 2. Casing - Means Unslotted Or Non-perforated Lining Tubes. 3. Development Equipment - Means High Velocity Jetting Tool, Airlift Equipment, Surge Plunger And All Other Equipment Needed To Develop The Well. 4. Diameters - Means Nominal Diameters Unless Otherwise Stated. 5. Drilling Rig - Means The Drilling Equipment And The Auxiliary Equipment For Its Operation. 6. Drilling Unit - As Defined In Section B.b. 7. Final Well Design - Means The Drawing And Description Prepared By The Engineer Upon Completion Of Drilling Specifying The Final Well Construction. 8. Lining Materials - Means Any Casing, Screen, Slotted Lining Or Perforated Lining Tube Whether Permanently Or Temporarily Installed In The Borehole. 9. Pumping Unit - As Defined In Section H.g. 10. Screens - Means Continuous Wirewound Stainless Or Low Carbon Steel Screens, Or Slotted Or Perforated Lining Tube. 11. Preliminary/tentative Well Design - Means The Contract Drawing Showing The Estimated Quantities Of The Work. 12. Well - Means Any Completed Hole In Which All Lining Material Has Been Set, All Grouting Completed And All Temporary Lining Removed. B. Technical Standards All Materials Or Workmanship Shall Comply With The Specifications. Other Standards Equal Or Superior To Those Enumerated In This Specification, Shall Be Acceptable, Subject To The Approval Of The Engineer. The Opinion Of The Engineer Must Be Obtained Prior To Utilizing Such Materials Or Workmanship On Or Off The Site. C. Water Supply And Illumination In The Absence Of Adequate Quantities Of Water Or Illumination Required For Drilling At The Drilling Site, The Contractor Shall Make Such Arrangements Including The Provision For Mobile Tanks Or Fixed Tanks As May Be Necessary To Ensure A Supply Of Water And Illumination Sufficient For Drilling Operations. D. Electrical Power Supply 1. The Contractor Will Make Arrangements As May Be Necessary For The Connection Of Or Supply Of Power To The Site. 2. Payment For The Provision Of Electrical Power Supplies As Specified In Section A.d.1. Shall Be Deemed To Be Included In The Rates Entered In The Bid Form For Setting Up Equipment At The Site, Drilling Rates And Rates Entered For Operation Of Pumping Unit. E. Storage Of Inflammables The Contractor Shall Comply With All Local Authority Regulations Applicable To The Use And Storage Of Diesel Oils, Petrol, Paraffin And Other Inflammable Fuels Used By Him/her On The Site, And Shall Ensure That Adequate Precautions Are Taken Against Fire. F. Boundaries Of Work The Owner Shall Provide Land Or Rights-of-way For The Work Specified In This Contract And Make Suitable Provisions For Ingress And Egress, And The Contractor Shall Not Enter Or Occupy With Men, Tools, Equipment Or Material, Any Ground Outside The Property Of The Owner Without The Written Consent Of The Owner Of Such Property. Other Contractors And Employees Or Agents Of Ckwd And/or The Owner May, For All Necessary Purposes, Enter Upon The Work And Premises Used By The Contractor, And The Contractor Shall Conduct His/her Work So As Not To Impede Unnecessarily Any Work Being Done By Others On Or Adjacent To The Site. G. Access Roads Construction Or Improvement Of Access Roads To The Wells Shall, Unless Otherwise Agreed, Be Done By The Contractor At His/her Own Cost, Which Is Deemed To Be Included In The Contract Sum. The Access Road Shall Be Kept In Proper Condition During The Entire Construction Period. H. Protection Of Site 1. Except As Otherwise Provided Herein, The Contractor Shall Protect All Structures, Walks, Pipelines, Trees, Shrubberies, Lawns, Etc., During The Progress Of His/her Work, Shall Remove From The Site All Drill Cuttings, Debris, And Unused Materials, And Shall Upon The Completion Of The Work Restore The Site As Nearly As Possible To Its Original Condition, Including Removal Of Access Tracks And The Replacement, At The Contractor's Sole Expense, Of Any Facility Or Landscaping Which Has Been Damaged Beyond Restoration To Its Original Condition, All To The Satisfaction Of The Engineer. 2. Water Pumped From The Well Shall Be Conducted To A Place Approved By The Engineer Where It Will Be Possible To Dispose The Water Without Damage To Property Or Creation Of A Nuisance. I. Site To Be Kept Tidy The Contractor Shall, At All Times, Keep The Site And All Working Areas In A Tidy And Workmanship Condition And Free From Rubbish And Waste Materials. J. Temporary Buildings For Use By Contractor The Contractor Shall Provide At The Site Of The Works Such Temporary Buildings, Tanks, Workshops, Etc. As May Be Necessary And Proper For His/her General Use In Connection With The Works, And For The Use Of Persons Employed By Him/her. The Nature Of The Buildings, Tanks, Etc. And The Positioning Of Them Shall Be Subject To The Prior Approval Of The Engineer And The Relevant Authorities. K. Shop Drawings 1. The Contractor Shall If Requested By The Engineer Prior To Start Of Each Operation, Produce For The Engineer's Approval Shop Drawings Showing Details Of Technical Operations Such As Test Of Plumbness And Alignment, The Method Of The Slotted Casing Production, If So Required, The Methods Of Placement Of Formation Stabilizer And/or Cement Grout, The Arrangement For Well Testing, The Method For Well Development And All Other Drawings Pertinent To The Well Drilling, Well Construction Operations And Well Development As Requested By The Engineer. 2. Shop Drawings Shall Be Completed With Respect To Dimensions, Design Criteria, Materials, Methods Of Constructions And The Like To Enable The Engineer To Review The Information As Required. L. Well Head Protection 1. At All Times During The Progress Of The Work, The Contractor Shall Protect The Well In Such Manner As To Effectively Prevent Either Tampering With The Well Or The Entrance Of Foreign Matter Into It, And Upon Its Completion He Shall Provide And Install A Well Head Cap Satisfactory To The Engineer. 2. In The Event That The Well Becomes Contaminated Or That Water Having Undesirable Physical Or Chemical Characteristics Has Entered The Well Due To The Negligence Of The Contractor, He/she Shall At His/her Own Expense Perform Such Work Or Supply Casings, Seals, Sterilizing Agents Or Other Materials As May Be Necessary To Eliminate The Contamination Or To Exclude Any Undesirable Water In The Well. M. Transport Of Personnel And Equipment 1. The Contractor Shall Supply And Operate All Transport Required For Transporting His/her Employees, Materials And Equipment. 2. The Cost Of Movement Of Personnel, Materials And Equipment Shall Be Included In The Rates Given For Drilling, Development And Pump Operation. N. Site Preparation And Reinstatement 1. The Contractor Shall Prepare The Site, Provide All Necessary Tanks And Pits And Make All Necessary Arrangements For Erecting And Dismantling The Drilling Unit And Shall Reinstate The Site On Completion Of Such Phase Of Work To The Satisfaction Of The Engineer. 2. Payment Shall Be Deemed To Be Included In The Items Entered In The Bid Form For Erection And Dismantling Of Drilling Rigs. O. Standing Time Standing Time Will Be Paid Only When Drilling Is Suspended On The Written Instruction Of The Engineer Beyond Ten (10) Days Cumulative And For Reasons Not Attributable To The Contractor. B. Well Drilling A. Scope 1. The Contractor Shall Provide And Operate Three Or More Mobile Rotary Drilling Units Required To Complete The Works Within The Ninety (90) Calendar Day Contract Period. 2. The Contractor Shall Provide All Auxiliary Equipment, Lubricants, Fuels And Spares Necessary To Keep The Drilling Rig(s) In Continuous Operation. B. Equipment 1. The Drilling Rig(s) Together With All Auxiliary Equipment And Personnel Shall Be Defined As The Drilling Unit(s). 2. The Drilling Rig(s) Together With All Auxiliary Equipment Must Be In Good Working Condition And The Rig Mast Should Have A Vertical Height Of At Least Ten (10) Meters. 3. All Rigs Shall Have Sufficient Capacity To Drill The Specified Borehole(s) In The Diameters Specified In The Tentative Well Design(s) To A Depth Which Is Min. 25% Higher Than Indicated In The Contract Drawings. 4. Payment For Drilling Will Be By The Linear Meter Of Borehole As Measured After Removal Of Drill String. The Rates Set Against Drilling Items In The Bid Form Shall Be Deemed To Include All Equipment, Personnel, Fuels And Lubricants And The Accessories Required For Operation Of The Drilling Unit. 5. When The Drilling Unit Is Being Used For A Purpose Other Than Drilling, Then The Rates For That Purpose Entered In The Bid Form Shall Be Deemed To Include The Running Costs Of The Drilling Unit. C. Drilling Method 1. All Drilling Shall, Unless Otherwise Specified In The Special Conditions Of The Contract, Be Performed With The Rotary Drilling Method. 2. The Contractor Shall Drill The Hole To Such Depth And With Such A Diameter Which Shall Enable An Easy Installation Of Casing And Screen And Placement Of Gravel Envelope With A Uniform Thickness As Specified, If Required. During Drilling Of The Hole, The Contractor Shall Ensure That The Natural Permeability Of The Yielding Strata Near The Well Bore Is Not Irreversibly Reduced Due To The Drilling Method Employed. D. Strata Sampling 1. Strata Samples Shall Be Taken At 1 Meter Intervals Or More Frequent If The Formation Penetrated Changes. Samples Shall Be Placed In Plastic Or Other Appropriate Bags On Which Or In Which The Sampling Depth And The Date Of Sampling Is Written In Such A Manner That It Is Permanently Readable. 2. The Sampling Procedure Must Provide That All The Fractions Of The Penetrated Strata Are Present In The Sample. 3. Each Sample Shall Be Placed In A Wooden Box With Space For Storage Of One Sample And The Sampling Depth Shall Be Written On The Box. 4. A Record Of Samples Taken With The Details Described Above, Shall Be Submitted To The Engineer Everyday. 5. Payment For Sampling Shall Be Deemed To Be Included In The Rates Entered For Drilling In The Bid Form. 6. The Failure On The Part Of The Contractor To Obtain, Preserve And Deliver Samples Or Records, Satisfactory To The Engineer, Shall Be Considered As Actual Damage To The Owner. In The Event That, In The Opinion Of The Engineer, The Failure Of The Contractor To Take And Preserve The Samples May Affect The Proper Design Of The Well, The Contractor May Be Required To Perform Such Work As The Engineer Deems Necessary To Remedy Such Failure At No Cost To The Owner. E. Drilling Mud 1. Biodegradable Mud (revert® Or Similar) Should Be Used And Shall Be The Basis For The Priced Offer. The Contractor Is To Specify The Kind And Make Of The Additive And Its Properties In Section Vi Of The Bidding Documents. 2. Bentonite, If Used, Shall Be Of Premium Quality In Accordance With Api Standard 13a With 150 Kg/cum Of Make-up Water Yielding A Mud With A Viscosity Of Between 35 And 40 Seconds Using A Marsh Funnel And A Mud Weight Of Less Than 1.10 Kg/l (9.2 Lb/us Gal.). 3. Make-up Water Shall Be Treated With Caustic Soda (soda Ash) To Maintain The Ph Between 8.0 And 9.0 Prior To Mixing Mud. 4. During Drilling With Mud The Contractor Shall Perform Hourly Or Per Meter (as Directed By The Engineer) Measurements Of The Following Mud Characteristics: - Ph Value - Specific Gravity - Sand Content - Filtration Loss - Filter Cake Thickness - Funnel Viscosity The Recorded Mud Characteristics Shall Not Exceed The Following Values, Without The Prior Approval Of The Engineer: - Specific Gravity : 9.5 Lb/gal. (1142 Kg/m3) - Sand Content : 4% - Filtration Loss : 10 Ml - Filter Cake : 1.5 Mm F. Working Hours All Work From Start Of Drilling Of The Borehole Until Completion Of Well Development Shall, If The Rotary Drilling Method Is Applied, Be On A Round The Clock Basis. C. Geophysical Logging A. Scope The Contractor Shall, If Specified In The Special Conditions Of The Contract, Perform Geophysical Logging As Specified In The Special Conditions Of The Contract. B. Equipment 1. The Geophysical Logs May Be Recorded Either By Automatic Recording On A Chart Strip Or By Manual Reading Of Recorded Values. In Case The Logs Are Recorded By The Manual Method, Readings Shall Be Taken Per Min. 0.33 M Of Borehole Length. 2. The Recorded Logs Shall Be Submitted To The Engineer Immediately Upon Completion Of Logging As Plots Of Recorded Characteristics Versus Depth For His/her Approval. In Case Of Disapproval By The Engineer, The Logs Shall Be Repeated Immediately. C. Logs Geophysical Logging Shall, Unless Otherwise Specified In The Special Conditions Of The Contract, Comprise The Following Logs: Caliper Log Resistivity Log (16" And 64") Gamma Ray Log Self-potential Log (sp) D. Well Casing A. Scope The Contractor Shall Provide And Install The Well Casing Specified In The Contract Drawings And Any Temporary Casing Required During The Work, Unless Otherwise Specified In The Special Conditions Of The Contract. B. Casing Material 1. The Contractor Shall, Before Commencement Of Work, Submit For The Approval Of The Engineer The Following Details Of All Casing: A. Type Of Material B. Internal And External Diameters C. Wall Thickness D. Method Of Jointing E. Name Of Manufacturer F. Standard The Pipe Is Manufactured To 2. All Permanent Casing Material Shall Be Spiral Welded And Of New Stock Unless Otherwise Specified In These Documents. 3. The Contractor Shall Assume Responsibility For Any Casing Failure And Shall Correct, As Approved By The Engineer, Any Casing Failure At No Cost To The Owner. In The Event That The Contractor Cannot Correct A Casing Failure, The Contractor Shall Replace The Casing With Material Complying With The Specifications, Or If Necessary, Better Casing As Approved By The Engineer At No Extra Cost For Ckwd. C. Temporary Casing The Contractor Shall Provide Such Temporary Casing As May Be Necessary To Prevent The Collapse Of Any Formation During The Drilling Operation To Allow The Well To Be Sunk To The Specified Depth And To Allow The Insertion Of Permanent Lining Material As Required. The Contractor Shall Remove The Temporary Casing Before Completing The Well, Unless Otherwise Specified In These Documents. D. Lining Installation 1. Lining Material Shall Be Assembled And Located In The Well At The Required Depth In A Continuous Operation. The Lining Material Shall Be Set Concentric Within The Borehole By Centralizing Bars Unless Otherwise Agreed With The Engineer. 2. If The Lining Jams Or Is Lost Before It Is Set To The Specified Depth, The Contractor Shall Endeavor To Remove The Lining Material From The Well Or, If Unable To Effect Removal, Shall Redrill The Well And Replace The Lining Material At His/her Own Expense. E. Lining Material Accessories 1. The Contractor Shall Provide As Necessary The Following Accessories To Set The Lining Material To The Required Depth: A. Centralizers To Be Affixed To The Lining Material At Intervals Of 12 M To Locate The Lining Material In The Center Of The Drill Hole; B. Supporting Clamps, Equipment And Tools; C. Reducing Cones And Connecting Pieces; D. Casing Hangers E. All Other Necessary Equipment. 2. Except Where Expressly Provided, All Accessories Shall Be Deemed To Be Included In The Bid Form For The Provision And Insertion Of Lining Material. F. Testing For Plumbness And Alignment 1. All Boreholes Shall Be Constructed, Plumb And True To Line As Defined Herein. To Demonstrate The Compliance Of His/her Work With This Requirement, The Contractor Shall Furnish All Labor, Tools And Equipment And Shall Provide The Detailed Drawings And The Description Of The Tests To The Satisfaction Of The Engineer. 2. Tests For Plumbness And Alignment Must Be Made After The Complete Construction Of The Well And Before Its Acceptance. Additional Tests, However, May Be Made By The Contractor During The Performance Of The Work. No Specific Payments Shall Be Made For Making These Tests. 3. Should The Results Of The Tests For Plumbness And Alignment Show That The Plumb Bob Or Dummy Fails To Move Freely Throughout The Length Of The Lining Or Borehole To A Depth Of The Lowest Anticipated Pump Setting And Should The Well Vary From The Vertical In Excess Of Two-thirds Of The Smallest Inside Diameter Of That Part Of The Well Being Tested Or Beyond The Limitations Of This Test, The Plumbness And Alignment Of The Well Shall Be Corrected By The Contractor At His/her Own Expense. Should The Contractor Fail To Correct Such Faulty Alignment Or Plumbness, The Engineer May Refuse To Accept The Well And The Contractor Shall Drill A New Well Without Charge To Ckwd And/or The Owner. E. Well Screens A. Scope The Contractor Shall Provide And Install The Well Screens Specified In The Contract Drawings, Unless Otherwise Specified In The Special Technical Conditions. B. Type Of Screens 1. The Type Of Screens Shall Be As Specified In The Contract Drawings And The Special Technical Conditions. 2. Slotted Screens, If Specified For Installation, Shall Be So Fabricated As To Ensure The Maximum Yield Of The Well And To Prevent Clogging And Encrustation And Shall Be Free From Jagged Edges And Irregularities That May Accelerate Clogging Or Corrosion. C. Responsibility For Malfunction 1. The Contractor Shall Assume Full Responsibility For Any Malfunction Of The Screen Caused By Inadequate Installation Procedure And Shall Undertake Any Correction As Approved By The Engineer At No Extra Cost To The Owner. 2. The Screen Must Have No Change Of Alignment At Any Of Its Joints After Installation. If Requested By The Engineer, The Contractor Shall Submit For Approval By The Engineer The Design And Method Of Construction And Installation Of The Screen. 3. In The Event That The Contractor Cannot Correct A Screen Failure, The Contractor Shall Replace The Screen With Material Complying With The Specifications Of This Contract At No Extra Cost To The Owner. D. Screen Strength The Screens Shall Have Adequate Strength To Resist The External Forces That May Be Applied During And After Installation. E. Screen Accessories All Fittings, Packers, Couplings, Joints, Plugs And Seals Used During Installation Of Well Screen Together With The Installation Procedure, Shall Be To The Approval Of The Engineer. F. Formation Stabilizer/gravel Pack A. Scope The Contractor Shall Provide And Install Formation Stabilizer, Or Gravel Pack If Specified In The Contract Drawings And The Special Technical Conditions. B. Material 1. The Formation Stabilizer/gravel Pack Material Shall Consist Of Well Rounded, Water-worn Siliceous Grains. Angular Chipping Or Road Stone Must Under No Circumstances Be Used As Formation Stabilizer/gravel Pack Material. 2. The Contractor Shall, During The Mobilization Period, Submit To The Engineer For His/her Approval, Samples Of The Formation Stabilizer He/she Proposes To Use, Stating The Source Of The Formation Stabilizer, Quantities Available, Rate Of Delivery And Any Other Information Requested By The Engineer. C. Method Of Installation 1. The Method Of Placing The Formation Stabilizer/ Gravel Pack In The Annulus Shall Be Such That Separation Of The Gravel And Bridging Is Avoided. 2. The Formation Stabilizer/gravel Pack Shall Immediately Upon Completion Of Lining Installation, Be Placed In The Annulus Between The Borehole And The Lining, In The Screened Section(s) Of The Lining, As Specified In The Final Well Design. 3. If The Borehole Was Drilled By The Rotary Method, Installation Of Formation Stabilizer/ Gravel Pack Shall Be Done By Circulation Of The Drilling Mud. G. Well Development A. Scope 1. The Contractor Shall Furnish Compressors, Surge Plungers, Jetting Tools, Electric Generators, Chemicals And Any Other Equipment Required For Satisfactory Well Development And Shall Undertake The Development As Directed By The Engineer. 2. Development Shall, If The Percussion Drilling Method Is Applied, Comprise Surging With Plunger And Development By Airlifting Unless Otherwise Specified In The Special Technical Conditions. 3. Development Shall, If The Rotary Method Is Applied, Comprise Deflocculation, High Velocity Jetting In Continuous Slot Screens, Surging With Plunger In Slotted Screens And Development By Airlifting, Unless Otherwise Specified In The Special Technical Conditions. B. Surging With Plunger 1. Upon Completion Of Installation Of Lining Or Formation Stabilizer/gravel Pack, The Contractor Shall Develop The Well By Mechanical Surging With A Valve-type Surge Plunger Approved By The Engineer. 2. Before Start Of Surging And With 1 Hour Intervals During The Surging Operation, The Depth To The Well Bottom And To Top Of Gravel Pack Shall Be Recorded. 3. Surging Shall Be Continued Until Accumulation Of Sediments In The Sump Pipe, During A 1 Hour Period Surging Operation, Is Negligible. C. Deflocculation (applicable For Rotary Method Only) 1. Upon Completion Of Installation Of Lining Or Formation Stabilizer/gravel Pack, The Drilling Mud Shall Immediately Be Displaced From The Well By Pumping Clean Water Into The Sump Pipe. 2. Mud Displacement Shall Immediately Be Followed By Injection And/or Jetting Through The Screened Sections With A Mud Thinner To Deflocculate The Mud Cake On The Borehole Wall. The Well Shall Then Be Left For 12-24 Hours Before Developing Is Continued, To Allow The Mud Thinner To React. D. High Velocity Jetting 1. After The Deflocculation Material Has Been Allowed To Work For 12-24 Hours All Sections Screened With Continuous Slot Screens Shall Be Developed By High Velocity Jetting 2. The Jetting Tool Shall Be Equipped With Two Or Four Nozzles. The Nozzle Design Shall Be Such That It Produces A Concentrated Jetting Action. The Tool Shall Be Presented To The Engineer For Approval Before Start Of Drilling Operation. 3. The Jetting Tool Shall Be Supplied With Water Through A High-pressure Pump Capable Of Producing A Nozzle Velocity Of 50-70 M Per Second. The Pump Shall Be Equipped With A Suitable Pressure Gauge On The Discharge Side To Facilitate Monitoring Of Nozzle Velocity. 4. The Development Shall Be Carried Out By Slowly Rotating The Jetting Tool And Gradually Lowering It In Order To Cover The Entire Surface Of The Screen. 5. At The Same Time As The High Velocity Jetting Is Performed, The Well Shall Be Discharged With A Discharge Rate Slightly Higher Than The Discharge Rate From The Jetting Tool. 6. Each Section Of The Screen Shall Be Jetted Until The Return Water Is Free From Drilling Mud, But No Section Shall Be Jetted Less Than 20 Minutes Per Meter Of Screen. E. Development By Airlifting 1. Upon Completion Of High-velocity Jetting, And/or Surging With Plunger, The Well Shall Be Discharged By The Airlifting Method. 2. The Compressor Used For Pumping By Airlifting Shall Be Capable Of Developing A Minimum Pressure Of Not Less Than 250 Psi. The Delivery Shall Be No Less Than 21.25 Cum Air Per Minute. 3. The Quantity Of Water Discharged From The Well And The Drawdown In The Well At The Commencement Of The Development Shall Be Limited And Shall Be Gradually Increased Only As The Water Clears. From Time To Time The Air Flow Shall Be Stopped To Facilitate Loosening Of Trapped Sand Grains. The Well May Also Be Backwashed By Pumping Clean Water Into The Well. 4. During The Airlifting Operation, Position Of Air Pipe And Conductor Pipe, Drawdown In Well, Approximate Yield And Time For Each Change In Position Shall Be Recorded By The Contractor. 5. The Development Shall Be Completed With A Conductor Pipe Not More Than 0.5 M Above The Bottom Of The Well To Ensure That All Sand Has Been Cleaned Out Of The Sump Pipe. F. Well Cleaning Upon Completion Of The Development Operations, The Contractor Shall Demonstrate To The Satisfaction Of The Engineer That The Bottom Of The Well Is Clear Of All Sand, Mud And Other Foreign Materials. G. Freedom From Sand 1. The Contractor Shall Develop The Well By The Methods Specified Until The Water Pumped From The Well Is Substantially Free From Sand And Until The Turbidity Is Less Than 5 On The Silica Scale Described In Standard Methods Of Water Analysis (latest Edition As Published By Awwa, Apha And Wpct). 2. The Water Pumped From The Well Shall Not Contain An Amount Of Fine Material In Excess Of 1.0 Mg Per Liter When The Well Is Pumped At Its Maximum Expected Yield. The Equipment For Measurement Of The Sand Content Shall Be Furnished By The Contractor. H. Acceptance Of Development 1. The Development By The Specified Methods Shall Be Repeated And Continued Until The Well Is Thoroughly Developed In Accordance With The Criteria Specified In Section G.h. 2. If The Well Yield After The Well Has Been Confirmed Sand-free Is Still Below The Yield, Which Is Considered Acceptable For The Penetrated Aquifer, Then The Engineer May Instruct The Contractor To Perform Further Development. H. Well Testing A. Scope The Contractor Shall, Unless Otherwise Specified In The Special Technical Conditions, Provide And Operate A Pumping Unit For The Following Purposes: 1. Step-drawdown Pumping Tests On The Completed Well 2. Continuous Constant Discharge Pumping Test On The Completed Well. B. Equipment Capacity 1. The Contractor Shall Provide And Operate Pumping Machinery Capable Of Carrying Out The Specified Pumping And Shall Provide Adequate Controls To Allow Discharge Rates To Be Kept Constant At Varying Pumping Water Levels And To Permit Pumping With A Variation Of Not More Than 5% Of The Designated Discharge Rate During Any Period Of Yield Or Aquifer Testing. 2. The Pumping Unit Set Shall Be Able To Deliver A Discharge Rate, Which Is Min. 50% Higher Than The Expected Yield Of The Well And A Minimum Discharge, Which Is Maximum 15% Of The Expected Yield Of The Well When Suitably Throttled By Use Of A Gate Valve. 3. Suitable Pumping Machinery Will Be Deemed To Be: I. Submersible Electric Pump Unit Together With Generator And Such Accessories Needed To Run The Pump. Ii. Line-shaft Pump And Internal Combustion Prime Mover Together With All Accessories Needed To Run The Pump. C. Equipment Operation 1. The Contractor Shall Supply And Operate All Equipment And Accessories Necessary For Installation And Removal Of Pumps. 2. The Contractor Shall Maintain On Site Sufficient Fuels, Lubricants, Spares And Other Accessories Needed To Run The Pumping Unit For Whatever Period May Be Specified By The Engineer. 3. The Contractor Shall Provide Sufficient Competent Personnel Including A Qualified Fitter And Electrician, As May Be Necessary To Install And Operate The Pumping Unit. D. Control Of Discharge Rate The Contractor Shall, During The Pumping Tests, Provide A Suitable Gate Valve On The Discharge Pipeline, To Facilitate Easy Control Of The Discharge Rate. Discharge Shall Be Controlled With A Valve Fitted Behind The Elbow And Measured With A Water Meter, Fitted At A Distance Of Not Less Than 1 M Behind The Valve. An Additional Measuring Device (e.g. Oil Drum And Stopwatch) Shall Be Provided For Back Up And Checking. Drawdown And Recovery Of The Water Level Is To Be Monitored With A Water Level Indicator Through The Piezometer Pipe At Intervals As Specified By The Engineer On The Site. The Engineer May Demand Water Quality Measurements. He Will Provide The Monitoring Forms. E. Water Level Sounding Pipe 1. The Contractor Shall, If Instructed By The Engineer, Provide And Install A Temporary Tube Of At Least 1 Inch Diameter From The Top Of The Well To 2 Meters Above The Pump Bowl Assembly To Facilitate Easy Measurements Of Water Level. The Tube Shall Be Open Only At The Bottom And Top. 2. Payment For Providing, Installing And Removing The Tube Shall Be Deemed To Be Included In The Rates Given For Pumping Tests. F. Discharge Rate Monitoring Discharge Rates Up To 10 L/s (36 Cum/hr) May Be Measured By Drum Filling. Discharge Rates In Excess Of 10 1ps Shall Be Recorded With A Water Meter Or By A V-notch Weir Or With Orifice Discharge Pipe. All Items Are Subject To The Engineer's Approval Before Start Of Drilling. G. Definition Of "pumping Unit" The Equipment Specified In Section H.b – H.f Is Referred To As The Pumping Unit. H. Pumping Procedure The Engineer Will Determine The Pumping Procedure Necessary To Obtain The Objectives Of This Contract. I. Suspension Of Pumping If The Engineer Finds The Condition Of Any Equipment, Personnel, Fuel, Lubricants Or Accessories Will Prejudice The Quality Of Data Obtained From Any Pumping Test, He May Suspend The Work In Accordance With The Provisions Of The Conditions Of The Contract. J. Equipment Breakdown During Pumping 1. The Pumping Must Be Continuous And At A Constant Rate During The Pumping Tests. The Engineer Will Instruct The Contractor As To The Expected Maximum Duration Of Each Pumping Test Before Start Of Each Test. 2. If Pumping Is Interrupted Or The Discharge Rate Fluctuates By More Than 5% Of The Designated Discharge Rate, The Test May Be Repeated After A Period Of Recovery Determined By The Engineer. 3. If Any Pumping Test Is Interrupted Because Of Equipment Breakdown Or Inadequate Supervision Or Discharge Control, No Payment Will Be Made For Any Pumping Period Before Commencing The Test. K. Duration Of Tests 1. The Step-drawdown Pumping Tests Shall Be Performed On 5 Steps With A Duration Of 1 Hour Each. 2. The Continuous Constant Discharge Pumping Tests Shall Be Performed For A Period Of 3-5 Days, Unless Otherwise Specified In The Special Conditions Of The Contract Or Unless Otherwise Instructed By The Engineer. L. Temporary Pipeline 1. The Contractor Shall Provide A Temporary Pipeline As Directed By The Engineer For The Discharge From Pumping Tests And For Clearance To A Suitable Watercourse Or Drain. 2. Under Certain Circumstances When Re-infiltration Cannot Be Avoided Or It Is Costly To Provide For This Condition, The Engineer Shall Decide To What Distance From The Well, Water May Be Discharged On The Ground. I. Cement Grouting A. Scope The Contractor Shall, Unless Otherwise Specified In The Special Conditions Of The Contract, Provide The Cement And Mixing Equipment Required For The Mixing Of The Grouting Indicated In The Tentative Well Design And Shall Place The Cement Grout As Specified. B. Grouting Material 1. Cement Grout Shall Consist Of A Mixture Of 95% Portland Cement, 5% Bentonite And Clean Water, Mixed In The Proportion Of 52.5 Kg Of Portland Cement/bentonite To Max. 30 Liters Of Water. 2. All Cement Shall, Unless Otherwise Specified In The Contract Documents, Conform To The "specifications For Portland Cement" (astm C150-latest Revision). C. Method Of Placing Grout Material 1. The Method And Equipment For Placing The Grout Shall Be To The Approval Of The Engineer. No Method Will Be Approved That Does Not Provide For The Forcing Of Grout From The Bottom Of The Casing/hole/annulus To Be Grouted, To The Surface. Flushing Of The Annular Space With Fluid To Assure The Space Is Open And To Remove Loose Material Will Be Required To The Contractor Before Grouting Is Commenced. 2. Any Grouting Operation Shall Be Continuous And Before Starting, Sufficient Grout Shall Be Mixed To Complete The Whole Operation. During The Grouting Operation, The Mixed Grout Shall Be Continuously Stirred. The Contractor Shall Provide Such Tanks, Hoppers And Other Equipment As May Be Necessary To Meet These Requirements. D. Setting Time No Work Will Be Allowed On The Well Within A Period Of 72 Hours After Completion Of Grouting Unless Quick Setting Cement Is Used. In Such Case, The Idle Period May Be Reduced To 24 Hours Subject To The Engineer's Prior Approval. J. Well Completion A. Scope The Contractor Shall Provide And Operate All Equipment Necessary To Restore The Site As Near As Possible To Its Condition Before Commencement Of Drilling And Shall Furnish And Install A Well Head Cap As Specified In The Contract Drawings. B. Site Restoration The Site Shall Be Restored To A Condition As Nearly Possible To That Which Existed Before The Well Drilling And Testing Activities Commenced. This Work Shall Include, But Not Be Limited To, Restoration Of Fences And Structures, Removal Of Drill Cuttings, Leveling Of The Disturbed Ground Surfaces And Replacement Or Compensation For The Destroyed Plants And Landscaping. C. Well Head Capping The Well Head Shall Be Completed With A Well Head Assembly Fully Welded To The Upper Casing As Well As A Water Level Sounding Tube With Screw Cap In Order To Prevent Any Unauthorized Tampering Of The Well.