|Kala-Oya/Lunu-Ela 200m away from proposed Garbage site|
The surrounding area of the proposed garbage site is pristine Mangroves and the beautiful Kala-Oya. Maybe the animals and fish do not have a vote, whereas Kolonnawa is a large vote bank for Ranil Wickremesinghe. The idea is that garbage sites should be in less populous areas – not in residential areas. i.e. Send the garbage to where there are more animals than people.
The Colombo Garbage to Wilpattu has been revived and is about to be approved. Rumors have it that the Wildlife Dept was obstructing the approval. A change in Wildlife Dept leadership is planned and will approve the Garbage site adjacent to Wilpattu National Park and the beautiful Kala-Oya. Large amount of toxic chemical leachate (7 bowser loads, every day for at least 20 years) will end up in the Kala-Oya and the Puttalan Lagoon which is a enclose environment. (See Colombo Garbage to Wilpattu and Update: Colombo Garbage to Wilpattu and Suggestions: Colombo Garbage to Wilpattu)
The reason for all the chemical ending in the Lunu-Oya and Kala-Oya is because the underlying ground is limestone and very porous. Additionally the limestone and the High Density Polyethylene (HDPE) will crack because of blasting in the nearby active Holcim Quarry.
To quote from A case study on anticipated leachate generation from a semi-aerobic sanitary landfill at Aruwakkalu (Puttalam District) and its impacts (2015) by Ranil Kularatne
However, disposal to the Lunu Oya is not a good solution due to its almost stagnant nature. Furthermore, the proposed effluent treatment plant is likely to fail, with no mechanism to remove colloidals, COD and heavy metals, etc.
Therefore, releasing the effluent from the treatment plant to the Lunu Oya would result in intense pollution especially during the drier spells when discharge is very low due to high evapotranspiration and the leachate pollution would even spread to upstream areas (up to the zone of saline water intrusion) during the high tides.
The reduced, total organic carbon (TOC) rich mangrove sediments would become a crucial sink for the heavy metals due to adsorption and sulfate reducing bacteria (SRB) mediated dissimilatory SO42- reduction mechanisms; however, ingestion of contaminated sediments/detritus matter by bottom dwelling fauna wouldultimately result in bioaccumulation in higher trophic levelfaunal species such as Birds of Prey which are found inplenty due to the close proximity of the landfill site to the Wilpattu National Park (about 1.5 km to the boundary of the park, which is located towards the East of the landfillsite), one of Sri Lanka’s Ramsar wetlands. Also during high tidal events when there is saline water intrusion, there could be desorption of sediment adsorbed metals due to intense competition between Na? ions and metal ions for adsorption sites, resulting in an increased likelihood of the bioavailability of desorbed metals to fish, etc. in the long run considering that the Project area experiences a drier climate
However, operation of the nearby potential quarry sites (i.e., the Eluwankulama Forest; Fig. 1) for limestone extraction by Holcim (Lanka) Ltd (for cement production) could pose a danger to the single composite liner. This is because higher peak particle velocities due to the usage of detonators and charging drilled holes with ammonium nitrate/fuel oil and dynamite may rupture the HDPE liner and perhaps the soil bentonite layer too, ultimately leading to groundwater contamination.
|Map of Kala Oya and Garbage site. Click on Image for Google Maps|