Mercury Lamps and Water Issues
Return to Mercury and the Environment
Under federal hazardous waste laws spent mercury-containing lamps are considered hazardous when the concentration of mercury exceeds 0.2mg/l (in a prescribed solubility test known as the TCLP). Some states are more stringent than this and consider all spent mercury lamps to be hazardous.
There may also be environmental concerns about water quality (in the context of The Safe Drinking Water Act and The Clean Water Act, along with their enacting regulations) from the discharge of mercury from broken lamps. There is no significant research in this area, and it is not clear how these regulations may be applied. Preliminary studies suggest that mercury from lamps can impact water quality, whether the lamps are considered hazardous or not, when lamps are broken in solid waste containers where rainfall can enter and leak out. No one knows how many containers there are, how many will have tops open when it is raining or exactly how many lamps will break in any container, but we do know that there are still over 500 million mercury-lamps per year put into some type of solid waste container[1] and managed as municipal solid waste.
At some point all of these lamps break. General belief is that most of the breakage occurs in the container, as opposed to at the landfill, due to the fragile glass and compacting that occurs in containers. When these containers are also exposed to moisture from rain or other sources and they leak, or when they are washed out, mercury enters the environment. Studies have shown that when fluorescent lamps break in containers the mercury can hover for days, and eventually migrate downwind and back onto the land[2],[3]. But, there may be a more direct pathway to water.
One experiment was done to attempt to quantify this mercury/water pathway. Initial data suggests that any mercury-containing lamp, including lamps sold as “low mercury” or TCLP-passing, when broken in solid waste containers and enough water is present to escape the container, will leach detectable and possibly unacceptable amounts of mercury into the environment.[4],[5]
Is this relevant to water policies and water quality?
There are no specific regulations that address mercury-lamps in the context of water quality. It is not clear whether any discharge is regulated at these levels, or whether criteria apply only to point source discharges subject to NPDES, general storm water discharges, or other permit or regulatory conditions.
The Safe Drinking Water Act is a law that empowers EPA to set drinking water quality standards and requires drinking water suppliers to implement the regulations. Suppliers, in turn can regulate up stream sources to stay in compliance.
Safe Drinking Water Standards
Standards found at 40 CFR Part 141, and specifically at 40 CFR 141.23, 141.51 and 141.62. The Maximum Contaminant Level (MCL) for mercury is 0.002mg/l. Essentially, this means that up to 0.002mg/l of mercury can be in drinking water. More than that amount would have to be removed.
The Clean Water Act, Title III, Sections 303 and 304, is a law that empowers EPA to set standards for fresh and salt water quality, and allows states to regulate anything that impacts the total amount of a Priority Pollutant, including mercury, draining into fresh or salt waters of the state. States do this by establishing Total Maximum Daily Loading (TMDL) concentrations that accumulate in water bodies.
Clean Water Act Standards
The 1986 Quality Criteria for Water for Mercury is 40CFR 136.36:
Freshwater Aquatic Organisms and Their Uses:
Acute 0.0024 mg/l. Also known as Criteria Maximum Concentration (CMC), or the maximum amount that can be put in fresh water at one time.
Chronic 0.000012 mg/l. Also known as Criteria Continuous Concentration (CCC), or the amount that can continuously be put in fresh water.
Saltwater Aquatic Organisms and Their Uses:
Acute 0.0024 mg/l. CMC, or the maximum amount that can be put in salt water at one time.
Chronic 0.000025 mg/l. CCC, or the amount that can continuously be put in salt water.
EPA National Recommended Water Quality Standard
EPA has a National Recommended Water Quality Criteria for Priority Toxic Pollutants
Freshwater:
Acute 0.0014 mg/l. CMC, or the maximum amount that can be put in fresh water at one time.
Chronic 0.000077 mg/l. CCC, or the amount that can continuously be put in fresh water.
Saltwater Aquatic Organisms and Their Uses:
Acute 0.0018 mg/l. CMC, or the maximum amount that can be put in salt water at one time.
Chronic 0.000094 mg/l. CCC, or the amount that can continuously be put in salt water.
Human Consumption Standards
EPA also sets levels for human exposure to mercury from organisms in the water- 0.00014 mg/l.
EPA has recommended a lower level- 0.00005 mg/l for human consumption (see FR42160).
US EPA Reference concentration for mercury is 0.0003mg/m3, based on central nervous system effects after inhalation.
Comparison of different standards and initial study data
|
Standard |
Concentration of mercury |
|
TCLP |
0.2 mg/l |
|
Drinking water MCL |
0.002 mg/l. |
|
Water Quality CCC fresh |
0.000012 mg/l. |
|
Water Quality CMC fresh |
0.0024 mg/l. |
|
Human consumption |
0.00014 mg/l. |
|
Initial study rain simulation |
0.013- 0.031 mg/l |
As you can see there are several different standards, all of which are very low amounts. No direct cause and effect relationship has been studied between any of these standards and mercury releases from breakage in solid waste. However, empirical data indicate that the amount released from lamps could be a concern, and active diversion programs should be developed.
Other References
Drinking water: http://www.epa.gov/safewater/dwhealth.html
http://www.epa.gov/safewater/mcl.html
NPDES: http://cfpub.epa.gov/npdes/
http://cfpub.epa.gov/npdes/home.cfm?program_id=45
Stormwater: http://cfpub.epa.gov/npdes/home.cfm?program_id=6
http://cfpub.epa.gov/npdes/stormwatermonth.cfms
Water Quality: http://www.epa.gov/waterscience/standards/about/
http://www.epa.gov/waterscience/guide/
Non-point source pollution: http://www.epa.gov/owow/nps/
TMDLs: http://www.epa.gov/owow/tmdl/intro.html
[1] Container can mean a small “garbage” can typically found in janitor closets, dumpsters of all sizes, roll-off and other truck-loaded containers typically used for commercial buildings, compactors, hauling trucks, and more.
[2] Pathways of Mercury in Solid Waste Disposal, Preliminary Data Report, 2/6/99, S. Lindberg, K. Roy Owens, Oak Ridge National Laboratory, D.R. Reinhart and P. McCreanor, University of Central Florida, and Jack Price, Florida Department of Environmental Protection, Project Manager.
[3] S. Lindberg, "Florida Landfill- Mercury Air Surface Exchange Study, Preliminary Data Report," submitted to Florida Department of Environmental Protection, June 12, 1997. This report was done by Steve Lindberg of Oak Ridge National Laboratories, previously submitted to EPA as part of RCRA Docket Number F-97-FLEA-FFFFF.
[4] Maine Fluorescent Lamp Study, Final Report, December 19, 2001, conducted by the State of Maine, Department of Environmental Protection, Stacey Ladner, Principle investigator.
[5] Preliminary study, Southeast Recycling Technologies, Inc. Johnson City, TN, Storm Water Test, Alto Lamps, July, 2002, simulating rain-water discharge from solid waste containers into which Alto lamps had been broken with other trash. Non-scientific data show mercury concentrations in the water of 0.013- 0.031 mg/l, suggesting further testing is needed to determine relevancy to CWA and SDWA and impact on waters.