According to the Geological Survey of India (GSI), riverbed mining causes several alterations to the physical characteristics of both a river and riverbed. These can severely impact the ecological equilibrium of a river and damage plants, animals and riparian habitats. The GSI has issued guidelines to address the massive damage that riverbed mining can cause, including lowering the groundwater table in a floodplain. Excessive pumping out of groundwater during sand mining, especially in abandoned channels, generally results in depletion of groundwater resources causing severe scarcity and affecting irrigation and potable water availability.
In February 2012, the Supreme Court of India ruled that approval under the 2006 Environment Impact Assessment (EIA) notification is needed for all sand mining and gravel collection activities, even if the area being mined is less than 5 hectares (12.5 acres). It also made some critical observations related to environmental impacts of sand mining. Then in May of 2012, the Ministry of Environment and Forests (MoEF) issued an order mandating compliance with the Supreme Court’s February 2012 judgment and directing that permissions be sought for all mining activities. These permissions must come from the respective State Environment Impact Assessment Authorities (SEIAA) constituted under the 2006 EIA notification.
Some of the key features of illegal sand mining are:
1. Sand was being dredged illegally and operations were claimed to be carried out non-stop 24 hours a day all the year round including during monsoons.
2. Round-the-clock operations were facilitated by mechanical dredgers and suction pumps which were deemed to be illegal.
3. Several mangrove forests had been destroyed by illegal construction of storage docks, roads and other infrastructure to facilitate easy removal, storage and transfer of sand from the river. This made Mumbai and the neighbouring regions more vulnerable to floods.
4. Local people were denied a voice in the matter. Despite opposition from several Panchayats (local governments), dredging operations were still carried out with impunity because a mafia controlled the trade and many involved were either close relatives or friends of local politicians.
5. The livelihoods of local fishermen were being threatened by the sand barges which often destroyed their nets. Yet the fishermen claimed that no one was willing to register an official complaint. They were instead threatened and intimidated against making a fuss about such incidents.
6. Many institutional processes to promote consultation with various stakeholders were short circuited when consultations were sometimes deliberately scheduled at times that were inconvenient to the villagers. For e.g. in a village, that was predominantly Muslim, consultation meetings were scheduled on Friday afternoons. Since religious commitments took precedence, most villagers could not attend the consultations. This was then construed to be a lack of participation and decisions were made on their behalf.
The National Green Tribunal (NGT) issued a restraint order against all sand mining activity being carried out across the country without environmental clearance. The order was passed in the light of the recent controversy surrounding the suspension of IAS officer posted as sub divisional magistrate (SDM) in Greater Noida in Gautam Buddh Nagar in Uttar Pradesh after she cracked down on the mining mafia. While passing the order, NGT reaffirmed the Supreme Court’s order last year which banned any kind of mining of minor minerals, including sand, without environmental clearance from the Union Ministry of Environment and Forests.
A bench comprising justices Swatenter Kumar, U D Salvi, S N Hussain, and experts, D K Agarwal and Ranjan Chatterjee on Monday said that removal of minerals from river beds is posing a serious threat to the flow of rivers, survival of forests upon river banks and most seriously to the environment of river banks, especially those of the Yamuna, Ganga, Chambal, Gaumti and Revati rivers.
Some examples of steps taken by Kerala government to control illegal sand mining
• A round-the-clock complaint cell has been set up at the Collectorate Control Room for the public to register complaints regarding illegal sand-mining in the district. The cell will function for registering complaints. Appropriate directions will be given by the Additional District Magistrate (ADM) to revenue squads formed to check the illegal practice.
• Tahsildars have been asked to conduct raids, seize vehicles that engage in the illegal activity and bring them to the notice of District Collector.
• The Circle Inspector/Sub Inspector have been asked to take necessary steps to control the illegal activity by conducting raids as per the information received from the control cell.
• It has been asked to take the custody of the sand seized and sell it as per government rates. The Deputy Commissioner of Police (Law and Order) Thiruvananthapuram City and the Superintendent of Police (Rural) have been requested to provide armed police protection for providing protection to revenue squads.
Guidelines to control degradation given by Geographical survey of India
Following geo-scientific considerations are suggested to be taken into account for sand/ gravel mining:-
1. Abandoned stream channels on terrace and inactive floodplains may be preferred rather than active channels and their deltas and floodplains. Replenishment of ground water has to be ensured if excessive pumping out of water is required during mining.
2. Stream should not be diverted to form inactive channel,
3. Mining below subterranean water level should be avoided as a safeguard against environmental contamination and over exploitation of resources,
4. Large rivers and streams whose periodic sediment replenishment capacity are larger, may be preferred than smaller rivers,
5. Segments of braided river system should be used preferably falling within the lateral migration area of the river regime that enhances the feasibility of sediment replenishment,
6. Mining at the concave side of the river channel should be avoided to prevent bank erosion. Similarly meandering segment of a river should be selected for mining in such a way as to avoid natural eroding banks and to promote mining on naturally building (aggrading) meander components,
7. Scraping of sediment bars above the water flow level in the lean period may be preferred for sustainable mining,
8. It is to be noted that the environmental issues related to mining of minerals including riverbed sand mining should clearly state the size of mine leasehold area, mine lease period, mine plan and mine closure plan, along with mine reclamation and rehabilitation strategies, depth of mining and period of mining operations, particularly in case of river bed mining.
9. The Piedmont Zone (Bhabbar area) particularly in the Himalayan foothills, where riverbed material is mined. This sandy- gravelly track constitutes excellent conduits and holds the greater potential for ground water recharge. Mining in such areas should be preferred in locations selected away from the channel bank stretches. Areas where channel banks are not well defined, particularly in the braided river system, midstream areas should be selected for mining of riverbed materials for minimizing adverse effects on flow regime and instream habitat..
10. Mining of gravelly sand from the riverbed should be restricted to a maximum depth of 3m from the surface. For surface mining operations beyond this depth of 3m (10 feet), it is imperative to adopt quarrying in a systematic bench- like disposition, which is generally not feasible in riverbed mining. Hence, for safety and sustainability restriction of mining of riverbed material to maximum depth of 3m.is recommended.
11. Mining of riverbed material should also take cognizance of the location of the active channel bank. It should be located sufficiently away, preferably more than 3m away (inwards), from such river banks to minimize effects on river bank erosion and avoid consequent channel migration.
12. Continued riverbed material mining in a given segment of the river will induce seasonal scouring and intensify the erosion activity within the channel. This will have an adverse effect not only within the mining area but also both in upstream and downstream of the river course. Hazardous effects of such scouring and enhanced erosion due to riverbed mining should be evaluated periodically and avoided for sustainable mining activities.
13. Mineral processing in case of riverbed mining of the sandy gravelly material may consist of simple washing to remove clay and silty area. It may involve crushing, grinding and separation of valueless rock fragments from the desirable material. The volume of such waste material may range from 10 to 90%. Therefore, such huge quantities of mine wastes should be dumped into artificially created/ mined - out pits. Where such tailings / waste materials are very fine grained, they may act as a source of dust when dry. Therefore, such disposal of wastes should be properly stabilized and vegetated to prevent their erosion by winds,
14. Identification of river stretches and their demarcation for mining must be completed prior to mining for sustainable development.
15. The mined out pits should be backfilled where warranted and area should be suitably landscaped to prevent environmental degradation.
16. Mining generally has a huge impact on the irrigation and drinking water resources.
These attributes should be clearly evaluated for short-term as well as long-term remediation.
Thus, finally stated that miners can and should enrich rather than deplete the biodiversity as a corollary to their intervention in the ecology of their area of activity.
By Manoj K Jha
Part 2 of 2 article series