A water bore pump test or pumping test is a field study where a well is pumped at a controlled rate, water-level response is measured in nearby observation wells, optionally in the pumped well (control well); and then obtained data are used to determine the fluid conductivity, well performance, and aquifer confines. A good way of determining well performance and aquifer parameters is a water bore pumping test. In practice, the well’s zone of influence and well yield.
Water bore pump tests is implemented to assess how much groundwater may be drawn from a bore and information about the potential consequences of water withdrawals. A water bore pump test is frequently required when getting a resource consent to take groundwater to analyze the implications of taking water.
Sustainable Development Goal 6
According to reports, over 768 million people in underdeveloped countries lack long-term access to safe drinking water. SDG6 targets access to clean water and sanitation, with the goal of ensuring universal access to safe drinking water by 2030.
Types of Water Bore pump test
A step test is performed to measure how much water a bore can actually draw and how well it functions. Pumping the hole at a low rate is the first step of the test, followed by gradually raising the pumping rate to the maximum flow rate. During pumping, bore water level is measured.
A constant rate test (typically lasting 24 hours) is carried out to provide information on aquifer quality and the potential consequences of the additional take, such as on neighboring bores and streams. The bore is pumped at a constant rate, and the water level in the pumping and neighboring bores is checked.
Aims of water bore pump test
- Calculate the hydraulic properties
- Pumping experiments can identify and locate recharge and no-flow boundaries, which may also limit the lateral spread of aquifers.
- Pumping tests are the conventional method for determining in situ aquifer hydraulic parameters including as transmissivity and storage coefficients, as well as revealing the presence of any hydraulic limits.
- To ensure that the pumping and measuring equipment is working properly,
- To ascertain the consequences of abstraction on adjacent abstractions
- To evaluate the effect of the abstraction on the environment.
- To disseminate the details of the water quality
Required materials for water bore pumping tests:
- Generator
- Submersible pump
- Discharge pipe, connections
- Flow measurement device
- Tape measure, steel tape and carpenter’s chalk
- Pressure transducer, cables, data logger
- Electric water-level sounder and batteries
- Watches/stopwatches
- Barometric sensor/ thermometer
- pH and conductivity meters
- Sample bottles
- Toolkit, wires
- Data collection forms, log book, permanent-ink pens
- Computer, calculator
- Graph paper and/or computer software
- References, standard operating procedures
- Manufacturer’s operating manuals for equipment
- Maps, cross section.
Steps of water bore pump test
-
Designing a proper plan
Here are the following things that should be consider in the pre-planning stage:
- Time of year
- Natural variations that occur during the test
- Notify others who may be affected
- Type and depth of pump setting
- Pumping rate and duration
- Measurement and Control of the pumping rate
- Rate of measurements of the water levels
- Water levels in neighboring wells
- Discharge of pumped water
- Obtain water samples for water quality analysis
- Construction and site details of new and existing wells
- Policy for disposal of pumped water
- Assessment of aquifer properties from or previous work
- Potential for salt water intrusion
- Field equipment
- Forecast of test response
-
Undertaking the Water bore pump test
Water bore pump test is performed when a resources consent is requested or adjustments to an existing consent are made. When boring a new bore, the driller will supply data for analysis and may also recommend pertinent tests to undertake. A constant rate test involves pumping bore for usually 24 hours, and analyzing the bore level (before and after the test). If the bore is near a river or stream, a 72-hour test should be performed to provide better data for determining the effects on surface water. The water level in neighboring bores is also checked during the test (preferably 2 neighboring bores).
3. Analyzing the Data
The data is analyzed to identify the bore and aquifer properties. These variables can then be used to simulate the effects of your water take on nearby bores and surface water. We will supply you with a report containing this information, which you will submit together with your application.
Data from nearby bores is used to simulate the impact on surface water. A 72-hour test may be required to acquire better data in neighboring bores. Your neighbors will not use their bores during the water bore pump test, as this can alter the findings.
4. Monitoring Neighboring Bores
In addition to the pumping bore, it is recommended that you monitor at least two bores based on their position and depth during a constant rate test. It is beneficial to monitor at least one bore in the same aquifer as the pumping bore, as well as bores in shallower aquifers if they are accessible. This provides information on the relationship between shallow and deep aquifers, as well as the potential implications on stream flows. The monitoring bores should not be pumped during the constant rate test, and they should be turned off ahead of time to allow the water levels to stabilize and recover. If there are any other bores pumping nearby that could affect the findings of the constant rate test, they should be turned off both before and during the constant rate test. In practice, this may not be practicable, or the nearest bores may not be able to be monitored. If this is the case, you can try to find suitable alternatives, such as conducting the constant rate test during the winter when there is less pumping for irrigation, avoiding periods when water may be utilized for frost protection if there are orchards.
Duration of the test:
Pumping time is determined by the kind of aquifer and the level of accuracy sought in determining its hydraulic properties.
Water bore Pumping Test Report:
The formal report for a pumping test should be presented at the end of the project and include information about the persons engaged, pumping rates, the hydrogeological context, method of flow measurement, mapped aquifers, specific capacity, date of pumping test, available drawdown, all pump type data, depth of pump setting, method of water level measurements, water levels during the pumping test, observations made during the pumping test and duration of the test.
Limitations of water bore pumping tests:
Water bore pump tests, without a doubt, provide vital information and aid in understanding the groundwater system. However, judgments should be made with a broader understanding of regional geology, hydrogeology, and the environment in mind.
