1. Introduction

There are two types of underground water level monitoring wells:

+ The monitoring well uses a slit filter tube to monitor the common water level for many aquifers

+ Monitoring wells use standpipe filters, each well is usually used to monitor each separate aquifer

Figure 1. Common types of monitoring wells

Figure 2. Structure of monitoring well

2. Applicable standards

ASTM D 5092 – Installation and monitoring of groundwater levels by monitoring wells.

3. Equipment

3.1 Water level gauge

The water level meter is used to determine the water level inside the monitoring well. Some popular manufacturers in the world such as: Slope Indicator (USA), Yamayo (Japan), Sisgeo (Italy) ...

Measuring principle: When the probe touches the conductive medium forming a closed circuit, the lamp will light up and emit a signal sound.

Figure 3. Water level measuring device

How to measure:

- Turn on the power, adjust the scale to High

- Drop the probe into the well, when the probe touches the water, the indicator light will light up and sound "beep…beep"

- Read the indicator on the wire, that is the water depth compared to the top of the well tube

- Power off

3.2 Standpipe

The Standpipe Piezometer consists of a filter that attaches to a connecting pipe. The filter tubes have filter holes size 60-70 and are made from polyethylene or porous stone. The connecting pipes are usually made from PVC pipes.

3.3 Slot filter tube

The filter pipe is made from PVC, the body has grooves, which is a specialized device in the monitoring well.

4. Result

5. Pictures of the construction site