CLIENT: Kunsill Konsultattiv għan-Nofsinhar ta’ Malta (KKNM)
PROJECT BACKGROUND
The Kunsill Konsultattiv embarked on a project to remediate and restore Wied Blandun, which is located at the limits of Fgura.
Wied Blandun forms part of the drowned valley system of the Grand Harbour area. It is a 0.5 km long valley incised in Lower Globigerina Limestone at an elevation of about 35 metres above mean sea level. Its rainwater source is mostly run-off from the streets of Paola and Fgura.
The slopes of the valley consist of terraced fields divided by rubble walls. The terracing gives way to sloping banks and a wide watercourse bed. Most of the slopes are cultivated except for the very high grounds which are built-up. The northern valley sides (on the Għajn Dwieli side) are characterised by a series of steppe plains, a rocky belt and a gently sloping watercourse bank. The upper reaches of the valley, close to the road which leads to Fgura, support a vital stand of carobs (Ceratonia siliqua) and almonds (Prunus dulcis).
Wied Blandun valley is a Level 1 Site of Scientific Importance (geomorphology) and Level 4 Area of Ecological Importance as per Government Notice No. 938/01.
REQUEST
AIS Environment had been appointed to carry out all preliminary investigations of the valley that will serve to guide further qualitative and quantitative studies for Wied Blandun’s remediation and restoration.
The restoration was deemed necessary due to three main environmental problems the valley faced:
- Poor air quality (ozone, particulate matter and nitrogen dioxide)
- Drought and heat risk
- Loss of biodiversity & Ecosystem degradation
our input
Our team of experts conducted desktop and field surveys as part of this project. The preliminary studies involved geotechnical, hydrological, geological, biodiversity, historical, land use, social, and landfill investigations.
One of the project tasks was to identify and assess the impacts of historic and existing potential sources of contamination on sensitive environmental receptors within the valley. Potential sources of contamination could include chemical pollution, introduction of invasive species, noise pollution, etc. Sensitive environmental receptors are natural areas which could be exposed to contamination or pollution of various types.
results
The studies identified the following potential contamination sources on Wied Blandun: flytipping, atmospheric pollutants, sewage leakages, noise impacts, leaching from nearby agricultural land, noise pollution, and others. The studies describe their impact on the following sensitive receptors: biodiversity, agriculture, geological formations, soil, the Mean Sea Level Aquifer. The results from these investigations were presented in a preliminary conseptual site model (PCSM).
AIS then used the PCSM to prepare methodologies for more detailed studies of Wied Blandun, namely on biological interactions, land contamination and groundwater contamination. These studies aided the client in carrying out more detailed investigations of Wied Blandun.
The final project task was to prepare a preliminary risk assessment of Wied Blandun. The extent, duration, pathway, effect, magnitude and probability were used to gauge the risks of these impacts. Concerning impacts included invasive species, tree pathogens, contamination from nearby agricultural land and others.
