Consultancy Services needed to provide Hydro-Geological Survey Services, Habitat for Humanity Kenya

Habitat for Humanity Kenya seeks to hire a Consultant/Consulting firm with the capacity to conduct a comprehensive Hydro-Geological Survey and related studies for identification of a borehole drilling site and supervision of the drilling process.

BACKGROUND AND RATIONALE

Habitat for Humanity Kenya (HFHK) is among the 70 country affiliates of HFH International. In Kenya, we were registered in 1982 as Non-Governmental Organization, with the goal of enabling low income families access decent and affordable shelter. In the last 40 years, HFHK has supported more than 56,000 families across 9 counties in Kenya through housing micro-finance and direct construction. We are currently operating in Laikipia, Homabay, Kisumu, Tana River and Machakos. Our Business Plan (2020-2025) has outlined four Programmatic Areas namely: Financing for owner-led construction; Settlement-Based Practice; Secure Land Tenure; Disaster Risk Reduction & Response (DR3).

The goal of our Programmatic Area on Settlement Based Practice, is to see safe, resilient and healthy communities settled within quality housing and with access to basic services and infrastructure. .In Kisumu County, HFHK is initiating a 3-year BMZ funded project along the flood plains of River Nyando in Ahero Ward (Dec 2021-Dec 2024). We are focusing on 6 villages within the sub-location of Kochogo South, supporting 881 households (4,000 villagers) to cope with the frequent cycles of drought and floods through social structures and physical infrastructures that will be established for management of Water, Sanitation and Hygiene (WASH) services. Water will be supplied from a solar powered borehole serving 5 water kiosks and 2 schools through a 10km pipeline.

Elevated at 1,142 meters above sea level, Kochogo Location has three sub-locations (North, Central and South). Our project area in Kochogo South sub-location (0.2418° S, 34.9010° E), stretching across 6 km from the border with Ahero Town in the North towards the Nyando Delta formed around the mouth of Lake Victoria in the South. The project area borders directly on the river bank in the south (protected by a dyke) and Ahero Rice Irrigation Field in the North.

The largest river in the area is Nyando River, whose basin area (3,450km2) drains into the Winam Gulf of Lake Victoria after traversing four counties (153km). Even though it is an important source of water for the people in the region, it floods and damages homesteads and farmlands in long rainy seasons. Situated along the wetland of Nyando Basin, Kochogo Location Kochogo Location is within the areas vulnerable to flooding in Nyando Sub county. It’s also among the densely populated areas in Nyando Sub-County. The residents of the sub-county draw their livelihood mainly from agricultural activities with are majority being subsistence farmers growing food crops (maize, millet and sorghum) and keeping livestock (cattle, goats, sheep and poultry). Apart from food crops, sugarcane and rice are grown in the district as cash crops. The sub-county has over 20 irrigation schemes which have potential to cover about 3000ha of rice. Besides agriculture and livestock production, there are communities within the district that depend on fishing especially along the shores of Lake Victoria. Sand harvesting activities in some parts of the sub-county is not organized hence threatening to expand gully erosions in some parts of the sub-county.

PURPOSE AND OBJECTIVES

2.1 Main Purpose

HFHK intends to supply water to villages in Kochogo South Sub-location through a 10km pipeline serving 6 water Kiosks. The purpose of the survey is to ascertains suitable sites for exploration of significant quantities of groundwater before carrying out any drilling exercise. We aim to ensures the best spot is selected according to the geological data. A combination of geophysical methods are to be applied in the assessment of geological sub-surface conditions, including the resistivity method, vertical electrical sounding (V.E.S) and horizontal electrical profiling (H.E.P). The consultant is expected to use hydro-geological data, maps, graphs and cross-section profiles to determination of important information such as; ground water condition, estimation of drilling depth and identification of stress areas.

2.2 Specific Objectives;

The main objective of this project is to carry out an Environmental Social Impact Assessment (ESIA) study, hydrogeological /geophysical survey study with the aim of identifying the aquifer system, to localize drilling site with high potential of good quality groundwater and finally to supervise the drilling process.

The survey shall be carried out in three phases:

1. Evaluating the groundwater situation based on compilation of existing relevant data (e.g. drilling logs) with additional classical hydrogeological field data collection (e.g. survey of water points, water levels, water quality) leading to the identification of favorable exploration zone
2. Carrying out groundwater exploratory field geophysical investigations to identify exact drilling locations,
3. Supervising the drilling process and on the spot reporting on the progress.

The survey will focus on site reconnaissance and site mapping, drilling of Trial Pits, Geophysical studies and field tests, determination Water consistence and Water flow and Hydro-dynamic tests. A report will be generated and submitted the hydro-geological survey to Water Resource Authority (WRA) to request for a drilling permit

SCOPE OF WORK

The hydrogeological/geophysical survey will be done within Kochogo South Sub-location. The consultant will conduct the following:

Phase 1: Assess groundwater situation and identify geophysical strategy

• Compile and analyze all the available hydrogeological, geological, climatic, meteorological and hydrological data of the area and its environs in order to
  • Assess geomorphological features relevant to groundwater dynamic process (e.g. drainage patterns, vegetation cover variations).
  • Assess the groundwater potential by establishing a water balance for the area to present a conceptual hydrogeological model of the investigation area
• Design an appropriate geophysical investigation strategy that is coherent with the agreed criteria and with the identified target aquifer type (porous, fractured or karstic), the expected depth of the target aquifer and the baseline elevation (estimated depth to groundwater which determines the minimum required investigation depths).
• Present for approval the Phase1-Hydrogeological Report, showing the outcomes of the geophysical investigation strategy

Phase 2: Geophysical investigation and selection of drilling sites

• Carry out the geophysical investigation according to the investigation strategy and interpret results: select the most suitable borehole drilling sites in the project area, also considering the legal framework and the requirements of the Water Act
• Conducts detailed reconnaissance survey of project area to determine location of boreholes and 6 water Kiosks. (GPS coordinates, water level measurements, TDS and EC, condition, usage and performance where applicable) inspection of geological, geomorphological and structural characteristics of the investigated area; verification of existing data and findings
• Present a Phase 2-Geophysical Report showing the results of the geophysical investigation, including the raw data sets, the qualitative interpretation of the type curves in terms of layer sequence (for VES investigations) and inversions results, and the identification of the drilling locations and precise description of drilling strategy
• Establish a Well Design as integral part of the Geophysical Report, aiming at maximizing water inflow and minimizing well-head-losses
• Mark the proposed drilling sites with a concrete marker, shown in topographical maps and indicated on appropriate site sketch maps. GPS coordinates have to be provided
• Compile the Phase 1 and Phase 2 reports into an intermediate hydrogeological/geophysical report and submit to HFHK for approval prior to the drilling process

Phase 3: Drilling supervision

• Assist in the application and follow-up of the borehole-drilling permits at the Water Resources Authority (WRA) and National Environmental Management Authority (NEMA) by submitting the required reports and provisional sum for the permits and related follow-up costs
• Assist in tendering by developing Bills of Quantities (BoQs) that will be used in seeking quotations from prequalified contractors during bidding process, as well as developing the contract documentation and specifications
• Supervise the drilling works and ensure the boreholes are drilled and completed according to stipulated technical specifications and sound professional standard, including the geological borehole logging and documentation of pumping test according to standard formats
  • Supervise and document on a daily bases the drilling, development and test pumping of the proposed boreholes and hand-in a daily drilling progress report to HFHK.
  • Ensure that the drilling contractor do water sampling, geological logging and water quality analysis (chemical and bacteriological).
  • Adapt the general well-design according to the specific conditions, basing it on the geological log and on the results obtained from the pumping test.
  • Supervise installation of screens, casings, gravel pack, impermeable seals, well-heads etc. Ensure that the recommended drilling depths, design and materials are followed and propose and carry out quality control measures upon well-completion, e.g. borehole camera inspection.
  • Prepare a detailed borehole completion report; with all necessary recommendations e.g. pump capacity, optimum depth of installation, periodic water quality analysis according to the standard format.
  • All these documents shall be summarized in a Phase 3- Drilling Report, which will also include a quality control review of the drilling report from the drilling contractor.
  • Compile the Phase 1, Phase 2 and Phase 3 reports into a comprehensive final report (2 hard copies plus softcopy including all the raw data) and submit to HFHK
• Obtain all certificates and required documentation from the driller and submit to HFHK Construction supervisor at the end of project closure
• Issue completion certificate for the release of retention moneys and the project defects liability period

DELIVERABLES AND TIMING

The consultancy is expected to start working on the study on the 1st of August 2022 for a duration of at least 3 months. Before heading out to carry out the assignment, the consultant is required to submit an inception report and defend the delivery plan through presentation to HFH Kenya management team as shall be scheduled by HFH Kenya during contracting of the assignment. The consultant is expected to work very closely with the HFH Kenya management, Kisumu County government, Water Resources Authority Kisumu, and local national government administration officials in carrying out the study. The deliverables of this assignment are as follows;

1. Inception report describing in detail how the consultant plans to deliver the integrated survey,
2. Environmental, Social Impact Assessment report,
3. Hydrogeological Report
4. Reconnaissance Report
5. Geophysical survey Report
6. Drilling Report
7. Bills of Quantities (BoQs)
8. Driller Contract with borehole specifications

The consultant will also be required to deliver to HFH Kenya all study materials including and limited to:

• Soft copies of all data sets both quantitative and qualitative.
• The geophysical interpretation model and the graphical plot of the curve and model for the hydrological survey.
• Any other non-consumable documents/items that will be used in the course of the planned consultancy.

QUALIFICATION AND EXPERIENCE

The potential Consultant should have the following qualifications;

• A Master or postgraduate degree in Hydrogeology/Geology/Geophysics or Environmental Sciences or engineering or water engineering.
• Must be registered by the Geological Registration Board and preferably an active member of the Geological Society of Kenya (GSK).
• A consultancy firm with proof of previous record of conducting hydrological research will be an added advantage.
• Knowledge of integrated water management and its relations to adequate and affordable housing and the challenges inherent in the country and/or professional experience working in the sector.
• At least 10 years proven experience in conducting and interpreting hydrological/geophysical survey using diverse techniques
• Proven experience in drilling supervision and borehole documentation.
• A reliable and effective analyst with extensive experience in conducting analyses and a proven record of delivering professional results
• Excellent computer skills and desirable skills in Arc GIS and groundwater modelling software’s.
• Excellent presentation and report writing skills.