J.2 Technical Specifications J.2.2 38 Boreholes Technical Specifications & Hydrogeological Survey.pdf

USAID/Maji na Usafi wa Mazingira (MUM) Activity

TECHNICAL SPECIFICATIONS

BOREHOLES DRILLING IN SUMBAWANGA, KALAMBO AND NKASI

DISTRICTS

(OCTOBER 2017 – SEPTEMBER 2018)

Table of Contents Preamble

Risk Mitigation Measures

Scope of Work

ANNEXES

Attachment A: Contract Conditions

Attachment E: Drilling Log Template

Attachment F: Sample Well Design

Attachment G: Sample of Water Quality results form

Preamble

Risk Mitigation Measures

To Minimize Boreholes drillings risks including costs, the following measures have been/should be considered.

1. MUM contracted a contractor with qualified staff and modern equipment. The hydrogeological report has detailed information for a best-informed decision-making process including 3D assessment with data for each borehole as summarized below.

Based on some of the existing data the report also indicates that there has been successful drilling for Nkasi and Sumbwanga districts as summarized below:

2. Payments will be based on actual work done. Boreholes will be drilled in two stages; a pilot hole of appropriate small diameter will be drilled to the recommended depth or depth approved by the supervisor/consultant’s drilling supervisor to determine quantity and quality of water in a well. If water of sufficient quantity and quality is found, then the hole will be reamed1 out to a bigger appropriate diameter. If water of sufficient quantity or quality is not found, then the borehole will be designated as dry, and the contractor will backfill it according to the drilling rules. This means that the contractor will be paid only for work done up to this level.

1 Reaming is a cutting operation that involves enlarging existing hole diameters.

3. Drilling works will be very closely monitored and supervised by the supervisor/consultant’s drilling supervisor to monitor the process and profiles/lithology of the area in accordance with the result of hydrogeological survey. Water testing for salinity will be monitored during the entire drilling period.

4. Borehole drilling shall be done by a licensed driller in compliance with the Guidelines for Groundwater Exploration and Well Drilling and shall carry out the drilling activities in a professional manner observing general and technical requirements.

5. A fixed unit price contract is proposed. The cost per borehole will depend on the actual work done on each borehole site.

6. To speed up the drilling process, drilling contractors invited must have at least two (2) drilling rigs/teams working concurrently to allow at least two boreholes drilled at same time

7. It will be more beneficial to MUM activity and RUWASA in respective districts if all 38 boreholes are drilled. These wells will be utilized by RUWASA if funds for MUM activity will not be sufficient to construct schemes on all 38 boreholes.

Scope of Work.

Drill thirty eight (38) productive boreholes with acceptable yields and quality of water for human consumption in Rukwa Region at Kanazi (1 site), Nkana (1 site), Mashete (2 sites), Miombo (1 site), Malongwe (2 sites), Kizi (2 sites), Londokazi (2 sites), Nkomanchindo (1 site), Milundikwa (1 site) Katani (1 site) and Namanyere town (3 sites) found in Nkasi District, Ngoma (1 site) and Katazi (1 site) found in Kalambo District and Laela small town (3 sites), Ulinji (1 site), Chombe (1 site), Tululu (1 site), Kiandaigonda (1 site), Kipeta (1 site), Kilyamatundu (1 site), Mpona (1 site), Kilando (1 site), Kituku (1 site), Kilangawana (1 site), Mpande (1 site), Maleza (1 site), Ilambo (1 site), Liwelyamvula (1 site), Tunko (1 site), and Kamsamba (1 site) found in Sumbawanga District as summarized in table 1 below

Table 1: New 38 proposed boreholes

No Locations Point Code

GPS

Coordinates

Recommended Depth (m)

Anticipated drilling technique

Ranking Approximate Distance from District Head office to the village (km)

Design Demand/desir ed quantity for the proposed scheme (m3/hr) for 20 years design period

Easting Northing Minimum (m)

Maximum (m)

Sumbawanga District Council

1 Ulinji Village Point A 357883 9110384 103 196 Air rotary 1 20 7.4

2 Laela Misheni Site 01

Point A 395847 9053119 131 188 Air rotary 1 10

156.0 3 Laela Misheni

Site 04 Point C 396179 9053277 79 208 Air rotary 1 10

4 Laela Misheni Site 05

Point F 396019 9053464 118 199 Air rotary 1 10

5 Tunko village Point A 407945 9040713 117 198 Air rotary 1 25 4.7

6 Kamsamba village

Point D 401205 9042142 111 168 Air rotary 1 25 1.5

7 Chombe Point D 414776 9052122 129 186 Air rotary 1 60 29.4

8 Tululu village Point C 421099 9053397 123 180 Mud and Air rotary 1 70 4.1

9 Ilambo village Point C 429479 9082410 119 200 Mud and Air rotary 1 75 5.0

10 Mpande village Point A 427213 9081985 120 217 Mud and Air rotary 1 75 3.0

11 Kilangawana village

Point A 425281 9081883 125 182 Mud and Air rotary 1 70 4.6

12 Maleza village Point A 423551 9080393 103 160 Mud and Air rotary 1 65 8.3

13 Kiandaigonda Village

Point A 410362 9059400 130 214 Mud and Air rotary 1 65 13.5

14 Kilando Village Point C 423116 9058704 131 188 Mud and Air rotary 1 80 1.0

15 Mpona village Point B 421319 9061864 131 217 Mud and Air rotary 1 80 6.3

16 Kituku Village Point A 417730 9067708 99 223 Mud and Air rotary 1 85 4.1

17 Liwelyamvula village

Point B 408133 9076326 128 185 Mud and Air rotary 1 90 5.4

18 Kipeta village Point A 418444 9073102 126 183 Mud and Air rotary 1 95 11.2

19 Kilyamatundu village

Point B 421303 9077226 128 185 Mud and Air rotary 1 100 14.3

Nkasi District Council

20 Namanyere - Majengo Village

Point B 314337 9121143 127 184 Air rotary 1 10

178.8 21 Namanyere -

Lunyala Village Point D 289874 9174879 128 185 Air rotary 1 10

22 Namanyere - Nkomolo Village

Point C 282248 9171622 111 168 Air rotary 1 10

23 Mashete B Village

Point A 295814 9181412 131 188 Air rotary 1 20

7.6 24 Mashete A

Village Point F 294786 9181275 103 160 Air rotary 1 20

25 Miombo Village Point B 300606 9173241 127 184 Air rotary 1 40 8.7

26 Londokazi Point A 304441 9166079 116 187 Air rotary 1 45 10.2

Village Site 1

27 Londokazi Village Site 2

Point D 305029 9166671 116 187 Air rotary 1 45

28 Milundikwa Village

Point A 318373 9149284 116 173 Air rotary 1 50 5.3

29 Malongwe Village Site 1

Point E 328275 9149686 111 168 Air rotary 1 51

5.7 30 Malongwe

Village Site 2 Point A 327249 9151084 111 168 Air rotary 1 51

31 Katani Village Point D 311507 9148018 126 183 Air rotary 1 50 8.9

32 Kanazi Village Point B 291029 9164998 131 188 Air rotary 1 10 6.4

33 Nkana Village Point D 314344 9121225 126 183 Air rotary 1 45 4.0

34 Nkomachindo Village

Point D 309386 9125448 103 160 Air rotary 1 56 3.7

35 Kizi Village Site

Point E 281048 9206087 123 180 Air rotary 1 36 8.9

36 Kizi Village Site

Point D 282850 9205691 126 183 Air rotary 1 36

Kalambo District Council

37 Ngoma Village Point A 338716 9049486 103 160 Air rotary 1 42 3.7

38 Katazi Village Point B 362220 9055759 91 148 Air rotary 1 47 7.2

Table 2: Approximate Distance from District Head office to the village (km)

No Locations Point Code

GPS Coordinates Recommended Depth (m)

Anticipated drilling technique

Ranking Approximate Distance from District Head office to the village (km)

Easting Northing Minimum (m) Maximum (m)

Sumbawanga District Council

1 Ulinji Village Point A 357883 9110384 103 196 Air rotary 1 20

2 Laela Misheni Site 01 Point A 395847 9053119 131 188 Air rotary 1 10

3 Laela Misheni Site 04 Point C 396179 9053277 79 208 Air rotary 1 10

4 Laela Misheni Site 05 Point F 396019 9053464 118 199 Air rotary 1 10

5 Tunko village Point A 407945 9040713 117 198 Air rotary 1 25

6 Kamsamba village Point D 401205 9042142 111 168 Air rotary 1 25

7 Chombe Point D 414776 9052122 129 186 Air rotary 1 60

8 Tululu village Point C 421099 9053397 123 180 Mud and Air rotary 1 70

9 Kiandaigonda Village Point A 410362 9059400 130 214 Mud and Air rotary 1 65

10 Ilambo village Point C 429479 9082410 119 200 Mud and Air rotary 1 75

11 Mpande village Point A 427213 9081985 120 217 Mud and Air rotary 1 75

12 Kilangawana village Point A 425281 9081883 125 182 Mud and Air rotary 1 70

13 Maleza village Point A 423551 9080393 103 160 Mud and Air rotary 1 65

14 Kilando Village Point C 423116 9058704 131 188 Mud and Air rotary 1 80

15 Mpona village Point B 421319 9061864 131 217 Mud and Air rotary 1 80

16 Kituku Village Point A 417730 9067708 99 223 Mud and Air rotary 1 85

17 Liwelyamvula village Point B 408133 9076326 128 185 Mud and Air rotary 1 90

18 Kipeta village Point A 418444 9073102 126 183 Mud and Air rotary 1 95

19 Kilyamatundu village Point B 421303 9077226 128 185 Mud and Air rotary 1 100

Nkasi District Council

20 Namanyere - Majengo Village

Point B 314337 9121143 127 184 Air rotary 1 10

21 Namanyere - Lunyala Village

Point D 289874 9174879 128 185 Air rotary 1 10

22 Namanyere - Nkomolo Village

Point C 282248 9171622 111 168 Air rotary 1 10

23 Mashete B Village Point A 295814 9181412 131 188 Air rotary 1 20

24 Mashete A Village Point F 294786 9181275 103 160 Air rotary 1 20

25 Miombo Village Point B 300606 9173241 127 184 Air rotary 1 40

26 Londokazi Village Site 1 Point A 304441 9166079 116 187 Air rotary 1 45

27 Londokazi Village Site 2 Point D 305029 9166671 116 187 Air rotary 1 45

28 Kanazi Village Point B 291029 9164998 131 188 Air rotary 1 10

Kalambo District Council

29 Ngoma Village Point A 338716 9049486 103 160 Air rotary 1 42

30 Katazi Village Point B 362220 9055759 91 148 Air rotary 1 47

Nkasi District Council

31 Milundikwa Village Point A 318373 9149284 116 173 Air rotary 1 50

32 Malongwe Village Site 1 Point E 328275 9149686 111 168 Air rotary 1 51

33 Malongwe Village Site 2 Point A 327249 9151084 111 168 Air rotary 1 51

34 Katani Village Point D 311507 9148018 126 183 Air rotary 1 50

35 Nkana Village Point D 314344 9121225 126 183 Air rotary 1 45

36 Nkomachindo Village Point D 309386 9125448 103 160 Air rotary 1 56

37 Kizi Village Site 1 Point E 281048 9206087 123 180 Air rotary 1 36

38 Kizi Village Site 2 Point D 282850 9205691 126 183 Air rotary 1 36

Notes:

● Exact Location and actual site for drilling will be confirmed at site using the GPS Coordinates for each site as shown in table above.

● Approximate Distance from District Head office to the village (km) are indicative, the contractor must take his/her initiatives to confirm the distances.

● Anticipated drilling techniques are indicative as per hydrogeological survey report.

● The contractor must mobilize a drilling rig and equipment able to drill up at least 25% deeper than the depths indicated in table 1.

● Recommended depth (m) is given in ranges of minimum and maximum depth. The actual drilled depth on site will be determined by the drilling supervisor/consultant based on quantity and quality of water at the depth not exceeding the max depth proposed in the survey report.

Detailed Technical Work

1. DRILLING

The work comprises the drilling, construction and pump test and water quality tests of productive boreholes on new confirmed 38 sites as detailed/listed in table 1 above.

Drilling The Bidder will use drilling equipment capable of drilling to a depth at least 25% deeper than the depth indicated in the hydrogeological survey report. The use of cable tool, rotary or down the hole-hammer (air percussion) rigs is acceptable. Upon the consultation and guidance provided by the drilling supervisor/consultant the Bidder will drill the actual depth on site, according to the geological and hydrogeological conditions encountered. All payment of drilled depth shall be paid based on actual drilled depth, quantity and quality as recorded in the signed drilling logs.

The well will be drilled in two stages. A pilot hole of appropriate diameter will be drilled to the drilling depth described above to determine quantity and quality of water in a well. If water of sufficient quantity and quality is found, then the hole will be reamed2 out to a maximum diameter of 203 mm (8 inches) for all sites except for Laela and Namanyere site whose maximum diameter is 254mm (10”) diameter or as otherwise specified by drilling supervisor supervisor/consultant. The Bidder will carry out a short-term airlift test to determine the quantity of water in the well. If water of sufficient quantity is not found, then the borehole will be designated as dry, and the Bidder will backfill it according to the drilling rules. The term dry borehole in this document means a borehole which has no sufficient yield less than 2000 litres per hour constant discharge.

Formation samples The Bidder must take one soil sample at every 2 metres during the drilling and at every change in formation. The Bidder will keep samples of the formation drilled. The samples will be placed in a properly packed and identified sample box. The Bidder will make them available to the Supervisor/consultant on request. The bidder is responsible to send drilled samples in 250g sealed containers to the respective area Basin Water Board authority.

Screens and Casings All casings and screens supplied by the Bidder shall be of the following specifications.

● Screen: Upvc screens, slot size 0.75mm, Minimum open area 5% based on nominal Internal diameter of

146mm, Screen strength 45N/m or its equivalent, 3-meter length, threaded flush plain maximum outside diameter of 165 mm

● Casings: Upvc casings, 146mm minimum internal diameter, collapsible resistance of 1.4Mpa at 12 PN, Threaded flush plain, 3-meter length, Maximum outside diameter of 165mm.

● Screen: Upvc screens, slot size 0.75mm, Minimum open area 5% based on nominal Internal diameter of

199mm, Screen strength 45N/m or its equivalent, 3-meter length, threaded flush plain maximum outside diameter of 225 mm - for Laela and Namanyere sites

● Casings: Upvc casings, 199mm minimum internal diameter, collapsible resistance of 1.4Mpa at 12 PN, Threaded flush plain, 3-meter length, Maximum outside diameter of 225mm - for Laela and Namanyere sites.

Well alignment A well must be tested for alignment by setting the drilling rig such that the drilling pipes are vertically set such that are perpendicular to the drilling point. If not, the well be rejected and no payments will be made for its drilling and completion.

Gravel packing

2 Reaming is a cutting operation that involves enlarging existing hole diameters

A properly graded and clean gravel pack will be placed in the annular space between the hole wall and the outer face of the casing according to the approved well design. The drilling supervisor/consultant must approve the well design including the configuration of both casings and screens, and gravels three (3) days prior to the installation. The gravel pack should be placed by the wash down method. The Bidder should guard against bridging and should measure the depth of the gravel pack during installation to ensure that this has not occurred. The gravel to be used should be washed quartz containing no more than 5% carbonate material and should be clean, well rounded and have a grain size of between 0.5 to 2.5cm diameter. The Supervisor/consultant shall inspect and approve the gravel prior to use. Prior to use the gravel should be stored in such a way that they cannot be contaminated.

Grout seal and backfill.

A bentonite grout seal of minimum 1m lengths must be placed above the gravel pack upon completion of well development. The annular space shall then be back filled with suitable inert material.

Well development The Bidder will develop the well by surging for a period of at least 4 hours or for as long as the drilling supervisor/consultant on site determines is necessary to determine the stable yield. Prior to development the well will be sounded and subsequently again after development of the well. Any sediment that has settled in the well will be removed. The Bidder will take any necessary steps to remedy a well that has sediment of more than 0.5m in depth after well development.

Hydraulic Testing Following completion of the installation and development of the well, hydraulic testing shall be carried out to determine the performance of the well and the aquifer for the well with yield equal and greater than of 2m3/hr.

The Bidder shall supply and operate pump and motor set(s) and a power unit capable of a discharge rate up to 30m3/hr and down to 1m3/hr against a minimum suction head of up to the maximum drilled depth. The pump(s) and power unit shall be capable of operating continuously for a minimum period of 24hours, at a constant discharge rate. The pump set must have a foot valve to control back flow to the well once the pump is shut off.

● The Bidder shall supply all additional equipment required to measure the yield and draw down. The discharge shall be kept constant by a gate valve installed on the discharge pipe, it’s expected that the discharge rate will not change by more than 5% from the average rate. Water delivered by the pump should be prevented from returning to the aquifer during the testing, by conveying through a flexible pipe a sufficient distance (as determined by site engineer). To measure the discharge rates a calibrated circular orifice or weir or a calibrated V- notch or calibrated water meter can be used. Water levels in the well should be measured using an electrical sounding device, accurate to 1mm. Supply of testing sets that does not meet the above specification supervisor/consultant will not be accepted.

The Bidder will communicate to the supervisor/consultant 3 days in advance the day the pumping test is to be carried out. The pumping test shall be conducted as below.

- Step Test: The well shall be pumped in incremental discharge steps while recording the draw down, at least three steps. Each step is to be pumped to a minimum of 90 minutes. Immediately after end of the last step a recovery draw down shall be recorded until recovery is within 10% of the original static water level (i.e.

90% recovery). The discharge rate for each step will be determined by the supervisor/consultant at representative site

- Constant discharge test: The constant discharge test shall be done to wells with yield equal to or more than 2m3/hr, following completion of the step test. The constant discharge test shall be conducted for a minimum period of 24 hours or as determined by the supervisor/consultant. The supervisor/consultant shall determine the discharge rate. Immediately after the termination of the constant discharge test a recovery draw down shall be recorded until recovery is within 10% of the original static water level (i.e. 90% recovery).

- The results of the pump test will be approved by the supervisor/consultant prior to the Bidder being allowed to move to the next drilling site. The contractor must follow the instruction and guidelines under this solicitation failure to follow the guidelines will result to rejection of the work done.

- Disinfection of the well

- Once the well has been completed and tested, the Bidder will sterilise the well with a chlorine solution yielding at least 50mg/l of active chlorine in all parts of the well. The chlorine solution may be prepared from calcium hypochlorite or sodium hypochlorite or gaseous chlorine. The chlorine solution should stay in the well for at least four hours at the specified concentration. The drilling supervisor/consultant should approve all compounds before being used.

Water Samples The Bidder will submit to drilling supervisor/consultant a water quality testing report done and certified by recognized certified laboratory. Water samples must be collected by the laboratory personnel. This must be done at the pilot drilling stage. The samples should be taken and stored in accordance with normal practice, to ensure that no contamination of the sample occurs. The laboratory analysis will include physical, chemical and bacteriological tests in accordance to the Tanzania water quality standards, USAID, and WHO standard. The use of recognized certified water quality laboratory for water analysis is a must.

Protection of the Well during Construction Maximum care must be taken to avoid the physical, chemical, or bacteriological contamination of the well during construction. The bidder must keep contaminants away from the borehole itself, slope the area around the well to drain flushed water away from the borehole and temporary caping the borehole at any time the drilling rig is not in operation. If the well is contaminated due to Bidder’s negligence, the Bidder will be obliged to remove the contaminant from the well at his/her own cost.

Temporary Lid The Bidder will provide a lid to be placed over the mouth of the well at any time the drilling rig is not in operation.

The lid will be placed on top of the well on completion of well construction.

Sanitary Protection Seal A well that have been successfully tested must have a proper protective sanitary seal cast in concrete to a ratio of 1:2:2 by the Bidder. The protective seal shall be placed from 1.0 metres below ground level to 0.25 metres above ground and will occupy 0.5m2 (0.7m square slab around the well spacing.

Attachment A: Contract Conditions

GENERAL CONDITIONS

Instructions

Instructions from the Supervisor/consultant to the Bidder shall be in writing. If an instruction is given orally the Bidder shall act on it and the instruction should be confirmed by the Supervisor/consultant in writing within four days.

The Bidder shall comply with any reasonable instruction given by the Supervisor/consultant nominated representatives to carry out the work, if the instruction is given within the authority of the representative as notified to the Bidder by the Supervisor/consultant.

Bidders General Responsibilities The Bidder shall with due care and diligence carry out and complete the drilling and completion of wells in selected villages in accordance with the requirement of the bid. The Bidder will supply all necessary tools, machinery, materials, and labour to carry out the work.

Quality of the Bidders Work The Bidder will carry out the work at least to the standard normally expected of a competent and experienced drilling Bidder. The Supervisor/consultant may reject and withhold payment for any work, which, in his opinion, is not in accordance with normally acceptable standards.

Site Supervision The selected bidder will be supervised on site by a MUM contracted specialist. Selected bidder will be required to submit daily drilling logs to the site supervisor.

Safety The Bidder is responsible for the safety of all site operations and any injury sustained to any person or property because of site operations. The drilling site should be protected keeping people away from machinery/equipment and all movable tools. The Bidder should provide protective gears to the drilling crew and any person involved in the activity including helmets, boots, gloves, overalls, and masks. This is a must and should be closely monitored on site.

The Bidder must carry out all drilling works in accordance with Tanzanian Environmental Laws and Regulations, Environmental Guidelines. In all cases the bidder should ensure that the drilling activities have minimum environmental and social disruption and comply with MUM Environmental Mitigation and Monitoring Plan (EMMP). The EMMP will be available separately.

Liability of the Bidder The Bidder should declare in writing that equipment is in good condition then be responsible for accidents that will occur on site due to the sub-standard equipment. The Bidder shall keep the Supervisor/consultant harmless against all claims arising from loss or damage to third parties.

Access to sites The supervisor/consultant will introduce the Bidder to the community then the Bidder must inspect the sites and satisfy himself regarding all aspects of the sites including access. The Bidder is responsible for mobilizing all necessary equipment to the sites. Should drilling sites become inaccessible due to abnormal weather conditions then the Bidder will be entitled to an extension of time to complete the Contract but not to additional payment.

Supply of screens and casings The Bidder will supply all UPVC casings and screens for incorporation into the works per the specification given in the scope of Work section. The supervisor/consultant will certify the screens and casings before being used. The Bidder prior to commencement of works should supply a sample of screen and casings to the supervisor/consultant for approval.

Clients General Responsibilities The Client shall pay the Bidder the sum of money in accordance with the provisions of the Contract.

Commencement of the work

The Bidder shall commence the work within two weeks after notification by the Client that he should commence the work. Each Borehole is estimated to take a maximum of 4 working days. The exact start date will be specified in the notification to start.

Completion of the work The whole of the works should be completed within a period agreed by both parties at the signing of the contract, or such extended time as may be allowed under the Contract or agreed between the parties.

Variations to the Contract The Client may make variations in the quantity of the works, as deemed necessary. The effect of any such variations shall be discussed and agreed in writing by the parties, including any adjustments required to the time for completion and/or sums due to the Bidder and/or Client.

Defects Liability Period Retention of 20% of the Total sum of the contract assignment shall be retained from the final payment until after the defect liability period is over, which will be a period of six-months from the date of the successful completion of 100% of drilling and pump test. It will be paid after that period if there is no defect due to the poor quality of the work or poor restoration of site done by the Bidder.

GOVERNMENT RULES AND REGULATIONS FOR DRILLING AND INSTALLING WATER WELLS IN TANZANIA

1. Each water well or borehole shall be given an identification number, its geographical position on the ground clearly indicated on a sketch map or in the report, name of its owner and the altitude above sea level of the ground surface at the well point.

1. The drilling technology to be applied to drill the well changes in diameter, depth to each water strike, as well as the depth of the ground water table from ground surface shall be indicated.

2. If the upper section of the well is in unstable rock formation temporary or permanent cemented casing shall be installed for an exploration or production well respectively.

3. A proper sanitary seal or intermediate seal shall be placed to preserve, conserve, and protect ground water resources or their quality and reservoir pressure potential. This should as well effectively prevent contaminated surface water from entering and mixing with aquifer waters.

4. If the well bottom finishes in soft, lose or weathered rock formation, it shall be ensured that proper well bottom plug is inserted, or a cement seal is placed.

5. While drilling, the Bidder /Driller shall ensure that rock or soil samples are properly collected and thus be representatives for intervals of everyone and half meters (1.5). Where the rock composition changes (if between the said intervals) this shall inspection. However, a small portion of each sample shall be noted in the driller’s report. The samples may be kept in Log Boxes at the field for inspection. However, a small portion of each sample shall be placed in a plastic bag and be properly labelled before it is delivered to the respective Engineer who will later post it to the Head of Hydrogeology Unit of the ministry of Water for his action.

6. IF any borehole geophysics is undertaken, all relevant details of the exercise shall be recorded.

7. All casing and screens to be installed in a production water well shall be properly chosen so as to prevent chemical and / or galvanic corrosion and thus guarantee structural integrity of the well long life and good quality water.

8. For all well with artificial filter, the selection of gravel pack material, grain size, shape and installation method shall be carefully undertaken, after carrying out sieve analysis of aquifer material, to ensure well efficiency is not lower than internationally accepted standards. The thickness of gravel pack installed shall likewise satisfy the same conditions.

9. Internationally accepted methods of well cleaning, development, and pump testing shall be followed.

Evaluation of pump test results shall determine safe production limits, though actual extraction shall not exceed levels set by the granted water right of the well. Water quality (testing physical /chemical and if possible bacteriological). Shall be finally undertaken before concluding the pump test.

10. Water well sterilization must be undertaken after the well installation is completed to ensure that the water shall be safe for human consumption, hereby, internationally accepted standards shall apply as well.

11. Any drilled and abandoned borehole shall be professionally back-filled to protect and preserve ground water reserves as well as to eliminate any hazard to human beings who otherwise may fall into the hole.

12. Once a water well has been completed, a Completion Form shall be filled in. In order to certify correctness of its formation or contents, it shall be signed by the responsible Bidder /driller and counter signed by the Ministry of Water s Expert at Water Engineers Office .The Bidder /driller shall then produce sufficient number of copies of the completion form and distribute these to all relevant authorities including the Employer or well owner, the Principal Secretary of Ministry of Water (Attn. Head of Drilling Service) and the respective Water Engineer concerned.

The Head of Drilling of Ministry of Water or his representative shall visit any water well drill sites any time for inspection of drilling activities, for confirming drilling records or reports as well as providing technical advice where necessary. Such inspection report including recommendations shall be finally presented to the Ministry of Water for further action. The responsible water well Bidder /Driller shall inform his drilling team(s) in the field on this visiting mission(s) and shall provide such needed assistance to ensure that records are promptly obtained without inconvenience.

Attachment B: Drilling Log Template

Borehole Number: Date:

Location: Supervisor:

District: Weather Conditions:

Drilling Supervisor: ________________________ Drill Method:

Rig Type: Mud Pump Used: YES NO

Rig No: Pumping Rate:

Working Shift Standby Time:

Start Time: Contractor Supervisor/consultant

Finish Time: Start Time:

Total Hours: Finish Time:

Total Hours:

Breaks: (Hours) Reason:

Borehole Depth Borehole Diameter

Start of Shift Depth (m): Drilling: Pilot Hole Reaming Production

End of Shift Depth (m): Diameter (mm):____________________

Total During Shift (m): Bit Type _______________________________

Number of Samples Collected Water Level in Open Borehole

During Shift: Start of Shift (m)

End of Shift (m)

Aquifer Characteristics Aquifer Testing

Water Struck Est. Flow Material Type Duration (Hrs)

Depth (m) (m3/hr) V-Notch Height-average (cm)

Other Method: _______________________________

Measurement: _______________________________

Depth: airline (m) educator pipe (m)

Additional Comments or Problems

Site Engineer: Contractor:

BH Number: Date:

Depth Range Formation Details Borehole Drilling Method Sample

Diam (m) Collection

Casing Used Drilling Materials

Material Type: ___________________________ Drilling Muds Type: _____________________________

Diameter (m): _____________________________ Amount: _____________ m3

Total Length (m): _________________________ Additives Type: _____________________________

Amount: _____________ m3

Screen Used

Material Type: _____________________________ Well Completion

Diameter (m): ___________________________ Sanitary Seal ___________________ Each

Total Length (m): ________________________ Well Capping ___________________ Each

Site Restoration ___________________ Each

Observation / Dipper Line

Material Type:______________________________ Well Development

Total Length (m):_______________________ Development Time _____________ hrs

Screen Length (m):______________________ Additives Used _____________________________

Quantity _____________ kg

Well Materials

Bottom Cap Quantity: _______________ Eac h

Gravel Basket Quantity: _______________ Eac h

Well Disinfection

Centralizers (Set) Quantity: _______________ Eac h

Chemical Used _____________________________

Filter Pack Quantity: _______________ m3 Quantity __________ kg

Grout Seal Quantity: _______________ m3

Type: _________________________ Other

Well Alignment Test ___________________ Each

Inert Backfill Quantity: _______________ m3 Borehole Abandon ___________________ Each

Top Seal Quantity: _______________ m3 Temporary Casing

Type: _________________________ Diameter mm

Mix Ratio _______________ Length mm

Casing Retrieved YES NO

Mob - Demob Information

Demob from: ____________________________________ Mob to: _____________________________

Date of Departure: ________________________________ Date of Arrival: _______________________

Total Distance (km):

Site Engineer: Contractor:

Attachment C: Sample Well Design

STANDARD DESIGN FOR INSTALLATION OF BOREHOLES IN COLLAPSIBLE FORMATION

Attachment D: Sample of Water Quality results form

Attachment F: Hydrological Survey report

Maji na Usafi Wa Mazingira (MUM) Activity

HYDROGEOLOGICAL SURVEY REPORT ON IDENTIFIED SITES FOR BOREHOLES

DEVELOPMENT IN RUKWA REGION

May 2023

This publication was produced for review by the United States Agency for International Development by Tetra Tech, through the Water and Development IDIQ (Contract No. GS00Q14OADU138 / 72062121N00001 and Project No. REQ-621-21-000012 under the One Acquisition Solution for Integrated Services (OASIS) contract, Maji na Usafi wa Mazingira (MUM).

This publication was produced for review by the United States Agency for International Development by Tetra Tech, through the Water and Development IDIQ (Contract No. GS00Q14OADU138 / 72062121N00001 and Project No. REQ-621-21-000012 under the One Acquisition Solution for Integrated Services (OASIS) contract, Maji na Usafi wa Mazingira (MUM).

This report was prepared by WEMA Consult (T) Ltd for submission by:

Tetra Tech 159 Bank Street, Suite 300 Burlington, Vermont 05401 USA Telephone: (802) 495-0282 Fax : (802) 658-4247 E-Mail : international.development@tetratech.com

Tetra Tech Contacts: Lukas Kwezi, Chief of Party Email: LUKAS.KWEZI@tetratech.com Bradley Carr, Tetra Tech ARD Project Manager Email: brad.carr@tetratech.comv

USAID Contacts: Francis Mtitu, Contracting Officer Representative

U.S. AGENCY FOR INTERNATIONAL DEVELOPMENT

686 Old Bagamoyo Road, Msasani, PO Box 9130 Dar es Salaam, Tanzania E-Mail: fmtitu@usaid.gov

DISCLAIMER

This document is made possible by the support of the American People through the United States Agency for International Development (USAID). The contents of this report are the sole responsibility of Tetra Tech and do not necessarily reflect the views of USAID or the United States Government.

mailto:international.development@tetratech.com mailto:LUKAS.KWEZI@tetratech.com mailto:brad.carr@tetratech.comv mailto:fmtitu@usaid.gov

EXECUTIVE SUMMARY

This report presents the results of the groundwater survey undertaken by WEMA Consult (T) Ltd on behalf of TetraTech ARD/Maji na Usafi wa Mazingira (MUM). The groundwater survey was undertaken from 27th March to 21st April 2023. The objective of this study was to determine the potential areas for borehole drilling and comment on aspects of depth to potential aquifer, aquifer density, aquifer thickness and type as well as water type for selected areas. This site is within the jurisdiction of the Lake Rukwa and Lake Tanganyika Basin water Board respectively.

WEMA Consult employed a combination of electrical resistivity and magnetic techniques respectively to undertake this geophysical survey. As a result, a four-step methodology was adopted for this study. Firstly, the long ranger machine was used to scan the area of interest with highest amount of water at a diameter of up to 3,000 meters and a depth of up to 1,500 meters. In the second step, a geophysical machine with the ability to scan an area to the depth of 1,500 meters was employed to scan in detail the water potential areas identified in step one. The scanning exercise provided data in relation to aquifer thickness, aquifer density and water type. The third step involved the use of imaging system which provides the results in three dimensions (3D) of the step two output as well as precisely locating point for borehole drilling. The fourth step uses a 1-D machine to confirm the aquifer type (channel or basin) and thickness as established in step three as well as establishing the lithology of the area which will then inform on the best drilling method which can be used.

In general, results from this groundwater survey have good groundwater potential. For all selected points within surveyed sites in all districts, these recommended sites have desirable water type, aquifer depth, aquifer thickness, aquifer type and density respectively for borehole drilling. In addition, these points are located at a sufficient distance away from potential sources of pollution in compliance with the Guidelines for Groundwater Exploration and Well Drilling, 2019. It is our recommendations that (i) a water abstraction permit should be sought from Lake Rukwa and Lake Tanganyika Basin water Board office respectively before commencing any borehole drilling works to comply with section 54 of the Water Resources Management Act No.11, 2009 and Regulation 20 (1) of Groundwater (Exploration and Drilling) Licensing Regulations, 2013 (ii) borehole drilling works shall be done by a licensed drilling contractor under the supervision of the Consultant in compliance with the part 3.2 (A) of the Guidelines for Groundwater Exploration and Well Drilling of 2019; and (iii) upon successful completion of the drilling work, sample of the water should be taken to a registered water quality laboratory for a full physical, chemical and bacteriological analysis before the water is put to any use.

Table of Contents

EXECUTIVE SUMMARY iii

List of Figures vii

List of Tables xviii

List of Acronyms and Abbreviations xx

CHAPTER ONE 1

1.0 1

1.1 1

1.2 1

1.2.1 1

1.2.2 1

1.3 2

CHAPTER TWO 3

2.0 3

2.1 3

2.2 3

2.3 5

CHAPTER THREE 8

3.0 8

3.1 8

3.1.1 8

3.1.2 10

3.2 11

3.2.1 11

3.2.2 11

3.2.3 11

3.2.4 11

CHAPTER FOUR 12

4.0 13

4.1 13

4.2 13

4.2.1 13

4.2.2 18

4.2.3 24

4.2.4 30

4.2.5 38

4.2.6 46

4.2.7 54

4.2.8 62

4.2.9 70

4.2.10 76

4.2.11 82

4.2.12 87

4.2.13 93

4.2.14 105

4.2.15 116

4.2.16 122

4.2.17 130

4.2.18 136

4.2.19 141

4.3 146

4.3.1 146

4.3.2 151

4.3.3 157

4.3.4 166

4.3.5 174

4.3.6 182

4.3.7 189

4.3.8 195

4.3.9 203

4.3.10 208

4.3.11 216

4.3.12 223

4.3.13 229

4.3.14 234

4.3.15 242

4.3.16 249

4.3.17 256

4.4 263

4.4.1 263

4.4.2 271

CHAPTER FIVE 271

5.0 278

5.1 278

5.1 287

REFERENCES 281

ANNEXES 282

Annex 1: A list of RUWASA, WSSAs staff and Tetra Tech/ MUM Interns trained during the field exercise. . 282

Annex 2: Site Evaluation Report for Borehole Development Recommended Site

Annex 3: Resistivity Value for the Surveyed sites in Kalambo and Nkasi District Councils

LIST OF FIGURES

Figure 1: Location map of the surveyed project sites (Source: WEMA Consult, 2023) 3

Figure 2: Geological Map of the of the surveyed project sites (Source: WEMA Consult, 2023) 5

Figure 3: Topographical Map of the surveyed sites within the study area (Source: WEMA Consult, 2023) 10

Figure 4: Detailed Survey Results of Groundwater at Point “A” at Ulinji village 13

Figure 5: Detailed Survey Results of Groundwater at Point “A” at Ulinji village 13

Figure 6: Type of water and Best Drilling location at Point “A” at Ulinji village 14

Figure 7: Detailed Survey Results of Groundwater at Point “B” at Ulinji village 14

Figure 8: Type of water and Best Drilling location at Point “B” at Ulinji village 15

Figure 9: Detailed Survey Results of Groundwater at Point “C at ulinji village 15

Figure 10: Type of water and Best Drilling location at Point “C at Ulinji village 16

Figure 11: Interpreted result for ERT Section (Ulinji village) 17

Figure 12: Detailed Survey Results of Groundwater at Point “A” at Laela Misheni Site 01 18

Figure 13: Type of water and Best Drilling location at Point “A” at Laela Misheni Site 01 18

Figure 14: Detailed Survey Results of Groundwater at Point “B” at Laela Misheni Site 01 19

Figure 15: Type of water and Best Drilling location at Point “B” at Laela Misheni Site 01 19

Figure 16: Detailed Survey Results of Groundwater at Point “C” at Laela Misheni Site 01 20

Figure 17: Type of water and Best Drilling location at Point “C” at Laela Misheni Site 01 20

Figure 18: Interpreted result for ERT Section (Laela Misheni site 01) 22

Figure 19: Detailed Survey Results of Groundwater at Point “A” at Laela Misheni Site 02 23

Figure 20: Type of water and Best Drilling location at Point “A” at Laela Misheni Site 02 24

Figure 21: Detailed Survey Results of Groundwater at Point “B” at Laela Misheni Site 02 24

Figure 22: Type of water and Best Drilling location at Point “B” at Laela Misheni Site 02 25

Figure 23: Detailed Survey Results of Groundwater at Point “C” at Laela Misheni Site 02 25

Figure 24: Detailed Survey Results of Groundwater at Point “C” at Laela Misheni Site 02 26

Figure 25: Type of water and Best Drilling location at Point “C”at Laela Misheni Site 02 26

Figure 26: Interpreted result for ERT Section (Laela Misheni site 2) 28

Figure 27: Detailed Survey Results of Groundwater at Point “A” at Laela Misheni Site 03 30

Figure 28: Detailed Survey Results of Groundwater at Point “B” at Laela Misheni Site 03 30

Figure 29: Detailed Survey Results of Groundwater at Point “C at Laela Misheni Site 03 31

Figure 30: Type of water and Best Drilling location at Point “C at Laela Misheni Site 03 31

Figure 31: Detailed Survey Results of Groundwater at Point “D” at Laela Misheni Site 03 32

Figure 32: Detailed Survey Results of Groundwater at Point “E at Laela Misheni Site 03 33

Figure 33: Type of water and Best Drilling location at Point “E” at Laela Misheni Site 03 33

Figure 34: Detailed Survey Results of Groundwater at Point “F” at Laela Misheni Site 03 34

Figure 35: Type of water and Best Drilling location at Point “F” at Laela Misheni Site 03 34

Figure 36: Interpreted result for ERT Section (Laela Misheni site 01) 36

Figure 37: Detailed Survey Results of Groundwater at Point “A” at Tunko Village 37

Figure 38: Type of water and Best Drilling location at Point “A at Tunko Village 38

Figure 39: Detailed Survey Results of Groundwater at Point “B at Tunko Village 38

Figure 40: Detailed Survey Results of Groundwater at Point “C at Tunko Village 39

Figure 41: Detailed Survey Results of Groundwater at Point “D” at Tunko Village 40

Figure 42: Detailed Survey Results of Groundwater at Point “D” at Tunko Village 40

Figure 43: Type of water and Best Drilling location at Point “D at Tunko Village 41

Figure 44: Detailed Survey Results of Groundwater at Point “E” at Tunko Village 41

Figure 45: Type of water and Best Drilling location at Point “E at Tunko Village 42

Figure 46: Detailed Survey Results of Groundwater at Point “F” at Tunko Village 42

Figure 47: Type of water and Best Drilling location at Point “F at Tunko Village 43

Figure 48: Interpreted result for ERT Section (Tunko village) 44

Figure 49: Detailed Survey Results of Groundwater at Point “A at Kamsamba village 45

Figure 50: Detailed Survey Results of Groundwater at Point “B at Kamsamba village 46

Figure 51: Detailed Survey Results of Groundwater at Point “C” at Kamsamba village 47

Figure 52: Type of water and Best Drilling location at Point “C at Kamsamba village 47

Figure 53: Detailed Survey Results of Groundwater at Point “D” at Kamsamba village 48

Figure 54: Detailed Survey Results of Groundwater at Point “D” at Kamsamba village 48

Figure 55: Type of water and Best Drilling location at Point “D” at Kamsamba village 49

Figure 56: Detailed Survey Results of Groundwater at Point “E” at Kamsamba village 49

Figure 57: Type of water and Best Drilling location at Point “E” at Kamsamba village 50

Figure 58: Interpreted result for ERT Section (Kamsamba village section 01) 51

Figure 59: Interpreted result for ERT Section (Kamsamba village Section 2) 52

Figure 60: Detailed Survey Results of Groundwater at Point “A” at Chombe village 53

Figure 61: Detailed Survey Results of Groundwater at Point “A” at Chombe village 54

Figure 62: Type of water and Best Drilling location at Point “A at Chombe village 54

Figure 63: Detailed Survey Results of Groundwater at Point “B” at Chombe village 55

Figure 64: Type of water and Best Drilling location at Point “B”. at Chombe village 55

Figure 65: Detailed Survey Results of Groundwater at Point “C” at Chombe village 56

Figure 66: Type of water and Best Drilling location at Point “C at Chombe village 56

Figure 67: Detailed Survey Results of Groundwater at Point “D” at Chombe village 57

Figure 68: Type of water and Best Drilling location at Point “D at Chombe village 57

Figure 69: Interpreted result for ERT Section (Chombe village section 01) 59

Figure 70: Interpreted result for ERT Section (Chombe village section 02) 60

Figure 71: Detailed Survey Results of Groundwater at Point “A” at Tululu village 62

Figure 72: Detailed Survey Results of Groundwater at Point “A” at Tululu village 63

Figure 73: Type of water and Best Drilling location at Point “A at Tululu village 63

Figure 74: Detailed Survey Results of Groundwater at Point “B” at Tululu village 64

Figure 75: Type of water and Best Drilling location at Point “B” at Tululu village 65

Figure 76: Detailed Survey Results of Groundwater at Point “C” at Tululu village 66

Figure 77: Type of water and Best Drilling location at Point “C at Tululu village 67

Figure 78: Interpreted result for ERT Section (Tululu Village) 68

Figure 79: Detailed Survey Results of Groundwater at Point “A” at Ilambo village 69

Figure 80: Detailed Survey Results of Groundwater at Point “B” at Ilambo village 70

Figure 81: Type of water and Best Drilling location at Point “B” at Ilambo village 71

Figure 82: Detailed Survey Results of Groundwater at Point “C” at Ilambo village 71

Figure 83: Type of water and Best Drilling location at Point “C” at Ilambo village 71

Figure 84: Detailed Survey Results of Groundwater at Point “D” at Ilambo village 72

Figure 85: Type of water and Best Drilling location at Point “D” at Ilambo village 72

Figure 86: Interpreted result for ERT Section (Ilambo Village) 74

Figure 87: Detailed Survey Results of Groundwater at Point “A” at Mpande village 75

Figure 88: Detailed Survey Results of Groundwater at Point “A” at Mpande village 76

Figure 89: Type of water and Best Drilling location at Point “A” at Mpande village 76

Figure 90: Detailed Survey Results of Groundwater at Point “B” at Mpande village 77

Figure 91: Type of water and Best Drilling location at Point “B” at Mpande village 77

Figure 92: Detailed Survey Results of Groundwater at Point “C” at Mpande village 78

Figure 93: Type of water and Best Drilling location at Point “C” at Mpande village 78

Figure 94: Interpreted result for ERT Section (Mpande Village) 80

Figure 95: Detailed Survey Results of Groundwater at Point “A” at Kilangawana village 81

Figure 96: Type of water and Best Drilling location at Point “A” at Kilangawana village 82

Figure 97: Detailed Survey Results of Groundwater at Point “B” at Kilangawana village 82

Figure 98: Type of water and Best Drilling location at Point “B” at Kilangawana village 83

Figure 99: Detailed Survey Results of Groundwater at Point “C” at Kilangawana village 83

Figure 100: Type of water and Best Drilling location at Point “C” at Kilangawana village 84

Figure 101: Interpreted result for ERT Section (Kilangawana Village) 85

Figure 102: Detailed Survey Results of Groundwater at Point “A” at Maleza village 86

Figure 103: Type of water and Best Drilling location at Point “A at Maleza village 87

Figure 104: Detailed Survey Results of Groundwater at Point “B” at Maleza village 87

Figure 105: Detailed Survey Results of Groundwater at Point “B” at Maleza village 88

Figure 106: Type of water and Best Drilling location at Point “B” at Maleza village 88

Figure 107: Detailed Survey Results of Groundwater at Point “C” at Maleza village 89

Figure 108: Type of water and Best Drilling location at Point “C at Maleza village 89

Figure 109: Interpreted result for ERT Section (Maleza village) 91

Figure 110: Detailed Survey Results of Groundwater at Point “A” at Kiandaigonda village 93

Figure 111: Detailed Survey Results of Groundwater at Point “A” at Kiandaigonda village 94

Figure 112: Type of water and Best Drilling location at Point “A” at Kiandaigonda village 94

Figure 113: Detailed Survey Results of Groundwater at Point “B” at Kiandaigonda village 95

Figure 114: Detailed Survey Results of Groundwater at Point “B” at Kiandaigonda village 96

Figure 115: Type of water and Best Drilling location at Point “B” at Kiandaigonda village 97

Figure 116: Detailed Survey Results of Groundwater at Point “C” at Kiandaigonda village 98

Figure 117: Type of water and Best Drilling location at Point “C at Kiandaigonda village 99

Figure 118: Detailed Survey Results of Groundwater at Point “D” at Kiandaigonda village 99

Figure 119: Type of water and Best Drilling location at Point “D” at Kiandaigonda village 100

Figure 120: Interpreted result for ERT Section (Kiandaigonda village) 101

Figure 121: Detailed Survey Results of Groundwater at Point “A” at Kilando village 103

Figure 122: Detailed Survey Results of Groundwater at Point “A” at Kilando village 104

Figure 123: Type of water and Best Drilling location at Point “A” at Kilando village 105

Figure 124: Detailed Survey Results of Groundwater at Point “B” at Kilando village 106

Figure 125: Type of water and Best Drilling location at Point “B” at Kilando village 107

Figure 126: Detailed Survey Results of Groundwater at Point “C” at Kilando village 108

Figure 127: Type of water and Best Drilling location at Point “C” at Kilando village 109

Figure 128: Detailed Survey Results of Groundwater at Point “D” at Kilando village 110

Figure 129: Type of water and Best Drilling location at Point “D” at Kilando village 110

Figure 130: Interpreted result for ERT Section (Kilando village) 111

Figure 131: Detailed Survey Results of Groundwater at Point “A” at Mpona village 112

Figure 132: Type of water and Best Drilling location at Point “A”…