The key role of environmental monitoring in construction projects

Environmental monitoring plays a key role in understanding, managing, and minimizing the impact an organization’s activities have on an environment.

Water quality monitoring is often recommended for road works to provide assurance of compliance with regulatory requirements and to ensure that environmental degradation does not occur because of the works. Where possible, pre-construction monitoring should be undertaken during the Environmental Impact Assessment (EIA) phase of the project. During construction phase monitoring, the objectives are to identify if water quality problems are occurring as the result of construction activities and to demonstrate compliance with legal and other monitoring requirements including the water quality criteria and/or targets for the project. Monitoring is generally undertaken upstream and downstream of the works. As the construction works mainly have an impact on the receiving waters during times of site discharge, upstream and downstream samples should be taken as soon as practical following rainfall events. Rainfall events refer to times when runoff from the site is entering the receiving waters through on-site sedimentation controls such as silt fencing or windrows or when sedimentation basins require maintenance discharge to restore their design capacity. Samples are typically monitored in situ for pH and turbidity.

Turbidity measurements have the advantage of providing site management with immediate data, while total suspended solids (TSS) may take one week or more to be analysed and reported.

The use of field water quality multiparameter meters that house multiple sensors capable of simultaneous readings have become more prevalent as part of an effective monitoring program.

Hanna’s HI9829 is an ideal meter for field measurement. The kit is supplied in a rugged, drop-proof carrying case with sensor storage, beakers, and solutions for calibration. The HI9829 probe is waterproof (IP 68) and has a durable, weighted cap to protect sensors in field environments and ensure the probe sinks. The multiparameter meter can measure up to 12 parameters simultaneously, featuring a fixed temperature sensor and 3 sensor inputs: one potentiometric sensor input for pH, pH/ORP, or ISE sensor; one dissolved oxygen sensor input; and one electrical conductivity or electrical conductivity/turbidity sensor input.

HI9829

The use of Hanna’s microprocessor-based multiparameter intelligent probes with HI9829 will provide reliable data collection that can lead to an improved scientific understanding of the interconnections between natural, chemical and geological processes and manmade pollution to effectively evaluate applications for waste discharge permits, remediate contaminated sites and to protect or restore biological resources.

The HI76x9829 probes utilize field replaceable sensors with auto-recognition. The sensors are housed with the probe electronics in a rugged housing and a water-tight cable connection. The HI76909829 probe allows conductivity, pH/ORP (or an ISE), and dissolved oxygen measurement. Other probe models allow turbidity and logging. Probes with the logging function have a logging memory that allows storage of up to 140,000 individual samples or 35,000 complete sample data sets with date and time stamp thus permitting up to a 70-day deployment with all channels logging at 10-minute intervals. The probe incorporates a temperature sensor for temperature compensation of all parameters. The probes are available with a choice of cable lengths such as 4m, 10 m and 20 m that utilize a DIN connection to interface with the meters. Logging probes can be connected directly to a PC with a USB adapter cable, and PC application software to download log files directly from the probes.

Hanna offers a selection of seven sensors to be used on the intelligent probes. Sensor replacement is quick and easy with screw type connectors and are colour coded for easy identification. The HI7609829-4 EC/turbidity sensor is field replaceable and offers readings from both parameters at the same time.

All potentiometric sensors feature a double junction design and are gel filled to increase resistance to contamination. One of the ISE sensors can be used in place of the pH sensor and is automatically recognized. pH in mV readings is also displayed — which is useful for troubleshooting.

Reliable temperature measurements are a critical parameter of aquatic system monitoring. Temperature and temperature changes due to water releases can affect the ability of water to hold oxygen as well as the ability of organisms to resist certain pollutants. The intelligent probes incorporate an accurate thermistor that changes predictably with temperature changes. Accurate temperature reading in degrees Celsius, Fahrenheit and kelvin are displayed and utilized by other detectors for temperature correction.

Typical areas of application for the HI9829 include surface and groundwater monitoring in the construction industry and mining sector, wastewater monitoring in the food and beverage industry, leachate, surface and groundwater monitoring at landfill sites and water monitoring in lakes, estuaries and catchment areas.

For more information on Hanna’s HI9829 multiparameter meter, please visit: https://hannainst.com.au/hi9829-02-multiparameter-ph-ise-ec-do-turbidity-waterproof-meter-with-gps-option