Mining companies need to keep up with tightening water discharge standards
Recent water shortages around the world have highlighted how quickly water is becoming the the most irreplaceable resource on our planet. Facing new water challenges, governments and jurisdictions are working across all sectors – agriculture, technology, industrial, commercial – to protect the future of water and ensure its long-term viability.
In the U.S., state and federal governments are tightening water discharge standards and the pressure is on mining companies to stay ahead of the game. As these regulations become reality, mining operations will be under increased public and regulatory pressure to implement updated water management plans and strategies for discharge water reuse.
Adapting to Changing Regulations
The National Pollutant Discharge Elimination System (NPDES) permit program, a component of the Clean Water Act (CWA), regulates water pollution in the U.S. by limiting the discharge of pollutants into American waters. The CWA does this, in part, by establishing total maximum daily loads (TMDLs) for pollutants, and categorizes water bodies as “impaired” if they do not meet the designated quality standards.
Most of the regulations are based on specific numeric limits that control the level of pollutants that can be discharged into water bodies – e.g., copper is limited to 3.7 micrograms per liter. But when addressing harmful nutrient discharges such as nitrogen or phosphorous, these limits have historically been based on narrative statements that reference “amounts that will cause an imbalance in flora and fauna in the water body,” rather than strict numeric levels. This has made it difficult to effectively manage nutrient levels within water bodies.
To address this, the EPA promulgated the National Numeric Nutrient Criteria Strategy under Section 303(d) of the CWA to determine specific numeric criteria for nutrients in water bodies. Today, six states – Florida, Minnesota, New Jersey, Rhode Island, Wisconsin and Hawaii – have developed numeric nutrient criteria, while five more (Connecticut, Georgia, New York, South Carolina and West Virginia) are working to expand their criteria. Additional states are expected to develop numeric nutrient criteria in the coming years.
A Look At Phosphate Mining in Florida
Phosphate mining has been well established in central and north central Florida for decades. But the state also boasts an enormous system of interconnected aquifers and intricate artesian springs – as such, legislators have worked diligently to establish default numeric nutrient criteria to govern the local industrial and mining operations, as well as other discharges, across its six watershed regions.
In 2015, a phosphate mine located in north central Florida partnered with the Suwannee River Water Management District and the Florida Department of Environmental Protection to develop a sustainable water reuse solution. The primary goals were to reduce the mine’s overall discharge and nutrient load, while also reducing the amount of water the mine was pulling from the Floridan Aquifer system.
The project relied on a pump station and conveyance system that would redirect water from the point of discharge back into the mine to be reused in surface water operations. The project, which was completed in August 2016, cost $3.6 million. The mine and the two government agencies came together on the project as funding partners.
The project was successful, as it reduced nutrient loading into the Upper Suwannee River by up to 140,000 pounds per year of total nitrogen and up to 110,000 pounds per year of total phosphorus. It also significantly reduced the mine’s groundwater needs by 20 million gallons per day, greatly benefiting the Floridan aquifer system, which feeds the natural springs in the area.
Proactive Companies Stand to Benefit
Federal, state and local commitment to ensuring water quality means that work on numeric nutrient criteria standards will continue. And based on a decade of water projections, it looks like these requirements will only become more stringent. If left unaddressed, these changing regulations have the potential to significantly impact how mining operations manage their discharge water.
The burden is on the mining community to remain ahead of – and in compliance with – these new standards once they are issued. Mining operations must develop water management plans that put them in compliance with changing numeric nutrient criteria – not just for today or tomorrow, but for the entire life cycle of the mine.
Developing partnerships to accomplish beneficial projects like the one referenced in this article is an effective and proactive approach to finding sustainable solutions. Proactive, forward-thinking mining companies will benefit – not only economically, but by helping to achieve environmental and sustainability goals, thereby reinforcing their social license to operate.