Do You Need to Remove Copper From Your Wastewater?

Do You Need to Remove Copper From Your Wastewater?

Copper can show up in waste streams generated by nearly any industry, including the mining and metals, electronics, power, construction, and pulp and paper industries, among others. While copper is fairly innocuous at very low levels, high quantities such as that found in some industrial wastewater streams can pose a hazard to human health and to the environment. But do you need to remove copper fro your industrial waste?

In this article, we’ll take a look at why you may need to remove copper from your wastewater, and explore the most common reasons why a facility may elect to implement treatment technologies to reduce copper.

What are the main reasons for removing copper from wastewater?

Copper is a naturally occurring element that exhibits both a high density relative to water, as well as toxicity at low concentrations. Due to these characteristics, copper is classed as a heavy metal, a grouping that includes many other metals and metalloids, such as mercury, cadmium, arsenic, chromium, and lead.

While small amounts of copper are necessary to support plant and animal life, copper can pose significant risks to the environment and to human health when excess levels are present in water and soil. In humans, long term exposure to slightly elevated copper levels can result in mild symptoms such as headaches and gastrointestinal upset. Chronic exposure to high levels of copper is linked to a number of severe health impacts, including cognitive impairment in adolescents, as well as diseases of the liver, kidneys, brain and nervous system.

As such, the chief reason that copper removal is necessary is to protect public health and safety, although there are also other reasons to consider copper removal as part of an overall wastewater treatment strategy. We’ll address these in more detail below.

Compliance with wastewater discharge regulations

To mitigate health risks and environmental impacts associated with copper, regulatory bodies have established contaminant limits that define the maximum concentration of copper allowable in wastewater. In the United States, the Environmental Protection Agency (US EPA) distinguishes between direct dischargers (who release effluents directly to waterways) and indirect dischargers (who route effluents to wastewater treatment facilities).  In either case, failure to comply with relevant discharge limitations can mean fines and legal action, which can be substantial.

Direct dischargers are subject to US EPA enforcement by means of National Pollutant Discharge Elimination System (NPDES) permits. NPDES permits specify limits on wastewater volumes and contaminant levels, as well as any compliance reporting requirements. Limits on specific contaminants, such as copper, are established based on US regulatory standards, which are complex, and can vary by industry, facility type, size and location. For example, the US EPA maintains different copper limits in wastewater from copper forming plants than for electronic component manufacturers, or other types of industrial facilities. Permissible average daily limits for copper in wastewater is generally lower than 1 mg/L, although some limits range up to more than 5 mg/L. If your facility discharges wastewater to US waterways, you will need to do so in compliance with a NPDES permit, including testing to ensure that copper content falls within acceptable levels. In short, you likely need to implement some means of copper reduction if your facility discharges waste to waterways and your copper content either regularly or occasionally exceeds the limits of your NPDES permit.  

Indirect dischargers, while not subject to NPDES permit requirements, must still comply with regulatory requirements enforced by the receiving facility. The US EPA has developed specific guidelines and limitations for centralized wastewater treatment facilities, which are defined as any facility that treats wastewater that originates offsite. This can include municipal or publicly owned treatment works (POTWs) who have the authority under the US EPA to enforce their own water quality standards. The US EPA defines several different levels of control for regulating wastewater discharge, with centralized wastewater treatment facilities generally required to keep average copper content levels in wastewater well below 1 mg/L. Given these stringent guidelines, a POTW may require that industrial facilities pretreat wastewater before discharge. In short, you may need to implement a copper removal strategy if your facility discharges wastewater to a POTW and your copper levels exceed the daily or monthly limits set by the receiving facility.

Environmental responsibility and stewardship

Many studies are still being conducted into the effects of copper as a pollutant, though observed environmental impacts include reduced plant biodiversity in contaminated areas, as well as damage to fish populations, and adverse health in other aquatic organisms. Additionally, copper adsorbs readily to organic material, such as that found in soil and sludge. When discharged to surface waterways, suspended particles of sludge or other organic material can carry copper far from the discharge point, potentially impacting ecosystems and water supplies across large distances. Copper does not degrade, and can therefore accumulate in soil, as well as in exposed plants and animals.

Given these characteristics, copper carries a clear capacity for environmental harm. For facilities that discharge wastewater high in copper, the failure to do so responsibly can therefore pose a reputational risk, especially in an era of growing public concern for environmental issues. Even when not strictly required by regulatory standards, for some companies, reducing copper in wastewater can be a valuable piece of an environmental stewardship program. 

Reclamation and recycling

Increasingly, facilities are motivated to seek copper removal technologies as part of a recycling and reclamation strategy. Separation technologies can indeed help to reclaim copper and other valuable materials from waste streams, allowing facilities to reuse or recycle them. If your facility is looking for ways to cut costs and improve material utilization, then copper removal and reclamation may be worth considering. Capturing copper from wastewater can offer a variety of cost savings benefits such as reducing demand for raw material, producing saleable byproducts, and cutting discharge costs by reducing the overall volume of wastewater, as in ZLD systems.

Can SAMCO help?

SAMCO has over 40 years’ experience custom-designing and manufacturing wastewater treatment systems, so please feel free to reach out to us with your questions. For more information or to get in touch, contact us here. You can also visit our website to set up a call with an engineer or request a quote. We can walk you through the steps for developing the proper solution and realistic cost for your wastewater treatment system to meet your copper and heavy metals removal needs.

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