Metals and acid mine drainage - Revision history

JeffreyJLukas at 21:28, 18 October 2023

2023-10-18T21:28:14Z

← Older revision		Revision as of 17:28, 18 October 2023
Line 1:		Line 1:
	==Overview==		==Overview==

	Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated in the headwater tributaries of the Upper Basin. Contamination is relatively ~~wide-spread~~ throughout these headwaters tributaries, and is found in tributaries to the Eagle, Gunnison, Animas, East, and Dolores Rivers; however, contamination rarely travels far downstream. The metal-rich geology in the Rocky Mountains creates natural background levels of metal contamination, which have then been exacerbated by 150 years of mining activities ~~and the~~ abandoned mines in Colorado (~~approximately~~ 5,100), Utah (~~approximately~~ 10,600), Arizona (~~approximately~~ 24,000) and New Mexico (~~approximately~~ 3,900) continue to contribute waters with elevated metals concentrations. Dissolved heavy metals require specific chemical conditions to persist as dissolved contaminants in water(e.g., low pH) and thus do not often propagate into the mainstem of the Colorado River.		Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated in the headwater tributaries of the Upper Basin. Contamination is relatively widespread throughout these headwaters tributaries, and is found in tributaries to the Eagle, Gunnison, Animas, East, and Dolores Rivers; however, contamination rarely travels far downstream. The metal-rich geology in the Rocky Mountains creates natural background levels of metal contamination, which have then been exacerbated by 150 years of mining activities. Thousands of abandoned mines in Colorado (~5,100), Utah (~10,600), Arizona (~24,000) and New Mexico (~3,900) continue to contribute waters with elevated metals concentrations. Dissolved heavy metals require specific chemical conditions to persist as dissolved contaminants in water (e.g., low pH) and thus do not often propagate into the mainstem of the Colorado River.

	[[File:AnimasMixingZone.jpeg\|thumb\|700px\|Figure 1: The mixing zone of the Animas River (left) and Cement Creek (right). Water in Cement Creek is metal-rich, low-pH while water in the Animas River has low metal concentrations and near-neutral pH. The dilution of Cement Creek in the Animas River increases the pH of Cement Creek water, leading many of the dissolved metals to precipitate back into solid form, from solution. (Photo credit: U.S. Geological Survey). ]]		[[File:AnimasMixingZone.jpeg\|thumb\|700px\|Figure 1: The mixing zone of the Animas River (left) and Cement Creek (right). Water in Cement Creek is metal-rich, low-pH while water in the Animas River has low metal concentrations and near-neutral pH. The dilution of Cement Creek in the Animas River increases the pH of Cement Creek water, leading many of the dissolved metals to precipitate back into solid form, from solution. (Photo credit: U.S. Geological Survey). ]]
Line 9:		Line 9:
	Acid mine drainage in the Colorado River Basin gained notoriety following the Gold King Mine Spill in 2015 in Cement Creek, a tributary to the Animas River, which flows into the San Juan River and the Colorado River. During the Gold King Mine Spill, 3 million gallons of acid mine drainage were accidentally released following remediation efforts on a collapsed mine tunnel. Since the spill happened abruptly, the acid mine drainage plume had severely concentrated metals and traveled downstream through the Animas River where the precipitating iron turned the stream a vibrant and alarming orange color. The spill resulted in extensive litigation between the states of Colorado, New Mexico, Utah, and Navajo Nation; following the Gold King Mine spill, the region was designated as an EPA superfund site.		Acid mine drainage in the Colorado River Basin gained notoriety following the Gold King Mine Spill in 2015 in Cement Creek, a tributary to the Animas River, which flows into the San Juan River and the Colorado River. During the Gold King Mine Spill, 3 million gallons of acid mine drainage were accidentally released following remediation efforts on a collapsed mine tunnel. Since the spill happened abruptly, the acid mine drainage plume had severely concentrated metals and traveled downstream through the Animas River where the precipitating iron turned the stream a vibrant and alarming orange color. The spill resulted in extensive litigation between the states of Colorado, New Mexico, Utah, and Navajo Nation; following the Gold King Mine spill, the region was designated as an EPA superfund site.

	~~==Relevance==~~
	Metal contamination in headwater tributaries typically impacts local communities immediately downstream; the Gold King Mine Spill was a notable exception. While metal contamination is insidious and poses many challenges for remediation, extensive cleanup work carried out by the EPA, nonprofits, and state and local agencies has improved metal concentrations in many reaches of headwaters streams in the Upper Colorado River. However, these improvements are complicated by continued sulfide mineral oxidation at abandoned mine sites and modern mines.		Metal contamination in headwater tributaries typically impacts local communities immediately downstream; the Gold King Mine Spill was a notable exception. While metal contamination is insidious and poses many challenges for remediation, extensive cleanup work carried out by the EPA, nonprofits, and state and local agencies has improved metal concentrations in many reaches of headwaters streams in the Upper Colorado River. However, these improvements are complicated by continued sulfide mineral oxidation at abandoned mine sites and modern mines.

JeffreyJLukas: /* Data and tools */

2023-09-14T15:21:41Z

Data and tools

← Older revision		Revision as of 11:21, 14 September 2023
Line 19:		Line 19:
	===[https://www.epa.gov/data EPA water quality database]===		===[https://www.epa.gov/data EPA water quality database]===
	The EPA reports and releases relevant data from acid mine drainage sites at which the EPA is involved. [https://www.epa.gov/goldkingmine/test2-data-gold-king-mine-response Specific pages] host data specifically relevant to the Gold King Mine spill (2015).		The EPA reports and releases relevant data from acid mine drainage sites at which the EPA is involved. [https://www.epa.gov/goldkingmine/test2-data-gold-king-mine-response Specific pages] host data specifically relevant to the Gold King Mine spill (2015).
			</onlyinclude>

	==Additional resources==		==Additional resources==

JeffreyJLukas: /* Relevance */

2023-05-30T16:55:13Z

Relevance

← Older revision		Revision as of 12:55, 30 May 2023
Line 10:		Line 10:

	==Relevance==		==Relevance==
	Metal contamination in headwater tributaries typically impacts local communities ~~on these smaller streams~~; the Gold King Mine Spill was a notable exception. While metal contamination is insidious and poses many challenges ~~to clean up efforts~~, extensive ~~efforts are ongoing. Clean-up~~ work carried out by the EPA, nonprofits, state and local ~~organizations~~ has improved metal concentrations in many reaches of headwaters streams in the Upper Colorado River. However, these improvements are complicated by continued sulfide mineral oxidation at abandoned mine sites and at modern mines ~~continues to contribute metal contamination to headwater streams~~.		Metal contamination in headwater tributaries typically impacts local communities immediately downstream; the Gold King Mine Spill was a notable exception. While metal contamination is insidious and poses many challenges for remediation, extensive cleanup work carried out by the EPA, nonprofits, and state and local agencies has improved metal concentrations in many reaches of headwaters streams in the Upper Colorado River. However, these improvements are complicated by continued sulfide mineral oxidation at abandoned mine sites and modern mines.

	==Data and tools==		==Data and tools==

TanyaPetach at 16:40, 16 May 2023

2023-05-16T16:40:55Z

← Older revision		Revision as of 12:40, 16 May 2023
Line 1:		Line 1:
	==Overview==		==Overview==

	Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated in the headwater tributaries of the Upper Basin. Contamination is relatively wide-spread throughout these headwaters tributaries, ~~ranging from~~ tributaries of the Eagle, ~~the~~ Gunnison, ~~the~~ Animas, ~~the~~ East, and ~~the~~ Dolores Rivers; however, contamination rarely travels far downstream. The metal-rich geology in the Rocky Mountains creates natural background levels of metal contamination, which have then been exacerbated by 150 years of mining activities. Dissolved heavy metals require specific chemical conditions to persist (e.g., low pH) and thus do not often propagate into the mainstem of the Colorado River.		Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated in the headwater tributaries of the Upper Basin. Contamination is relatively wide-spread throughout these headwaters tributaries, and is found in tributaries to the Eagle, Gunnison, Animas, East, and Dolores Rivers; however, contamination rarely travels far downstream. The metal-rich geology in the Rocky Mountains creates natural background levels of metal contamination, which have then been exacerbated by 150 years of mining activities and the abandoned mines in Colorado (approximately 5,100), Utah (approximately 10,600), Arizona (approximately 24,000) and New Mexico (approximately 3,900) continue to contribute waters with elevated metals concentrations. Dissolved heavy metals require specific chemical conditions to persist as dissolved contaminants in water(e.g., low pH) and thus do not often propagate into the mainstem of the Colorado River.

	[[File:AnimasMixingZone.jpeg\|thumb\|700px\|Figure 1: The mixing zone of the Animas River (left) and Cement Creek (right). Water in Cement Creek is metal-rich, low-pH while water in the Animas River has low metal concentrations and near-neutral pH. The dilution of Cement Creek in the Animas River increases the pH of Cement Creek water, leading many of the dissolved metals to precipitate back into solid form, from solution. (Photo credit: U.S. Geological Survey). ]]		[[File:AnimasMixingZone.jpeg\|thumb\|700px\|Figure 1: The mixing zone of the Animas River (left) and Cement Creek (right). Water in Cement Creek is metal-rich, low-pH while water in the Animas River has low metal concentrations and near-neutral pH. The dilution of Cement Creek in the Animas River increases the pH of Cement Creek water, leading many of the dissolved metals to precipitate back into solid form, from solution. (Photo credit: U.S. Geological Survey). ]]

	Sulfide-rich minerals, such as pyrite, react with oxygen and water to form sulfuric acid~~. The~~ sulfuric acid can then leach metals from surrounding host rock and these dissolved metals can travel downstream. Most metals are soluble only at acidic pH ~~meaning that these metals~~ precipitate back into solid form at near-neutral pH; most metal-rich acidic waters are attenuated at confluences with cleaner streams that have higher pH.		Sulfide-rich minerals, such as pyrite, react with oxygen and water to form sulfuric acid; this sulfuric acid can then leach metals from surrounding host rock and these dissolved metals can travel downstream. When this process occurs naturally, it is referred to as acid rock drainage; enhanced metal concentrations in waters due to mining activities is often referred to as acid mine drainage. Mining activities can increase the concentrations of heavy metals in water by crushing rock to increase surface area, digging tunnels which act as conduits of oxygen and water deep into the subsurface, and exposing new horizons of sulfide-rich minerals to oxidizing agents and water. Most metals are soluble only at acidic pH and precipitate back into solid form at near-neutral pH; most metal-rich acidic waters are attenuated at confluences with cleaner streams that have higher pH. Much of the contamination from acid mine drainage in the headwaters of the Colorado River has persisted for decades and is likely to continue given the complexity of the situation.
	Mining activities often increase the surface area of sulfide minerals that are in contact with oxygen and water. Metal leaching due to mining-exacerbated sulfide weathering is referred to as acid mine drainage and is a major contributor to dissolved metals in headwater streams. Much of the contamination from acid mine drainage in the headwaters of the Colorado River has persisted for decades and is likely to continue given the complexity of the situation. Limited cleanup funding, legal constraints surrounding the Superfund program, antiquated mining laws, mixed land-ownership, tenuous good-samaritan laws, and the perpetual nature of sulfide oxidation have limited the extent of mitigation. In particular, once surface disturbances cause additional sulfide minerals to be exposed to oxygen and water, stopping that sulfide oxidation is difficult, and solutions are costly.

	Acid mine drainage in the Colorado River Basin gained notoriety following the Gold King Mine Spill in 2015 in Cement Creek, a tributary to the Animas River, which flows into the San Juan River and the Colorado River. During the Gold King Mine Spill, 3 million gallons of acid mine drainage were accidentally released following remediation efforts on a collapsed mine tunnel. ~~Abandoned mines continuously leach acid mine drainage into Cement Creek and the spill volume was equivalent to the volume of acid mine drainage typically leaked in less than a week. However, since~~ the spill happened abruptly, the acid mine drainage plume had severely concentrated metals and traveled ~~farther~~ downstream the Animas River ~~than usual and~~ the precipitating iron turned the stream a vibrant and ~~disturbing~~ orange color. The spill resulted in extensive litigation between the states of Colorado, New Mexico, Utah, and Navajo Nation; following the Gold King Mine spill, the region was designated as an EPA superfund site.		Acid mine drainage in the Colorado River Basin gained notoriety following the Gold King Mine Spill in 2015 in Cement Creek, a tributary to the Animas River, which flows into the San Juan River and the Colorado River. During the Gold King Mine Spill, 3 million gallons of acid mine drainage were accidentally released following remediation efforts on a collapsed mine tunnel. Since the spill happened abruptly, the acid mine drainage plume had severely concentrated metals and traveled downstream through the Animas River where the precipitating iron turned the stream a vibrant and alarming orange color. The spill resulted in extensive litigation between the states of Colorado, New Mexico, Utah, and Navajo Nation; following the Gold King Mine spill, the region was designated as an EPA superfund site.

	==Relevance==		==Relevance==

TanyaPetach at 17:50, 15 May 2023

2023-05-15T17:50:53Z

← Older revision		Revision as of 13:50, 15 May 2023
Line 3:		Line 3:
	Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated in the headwater tributaries of the Upper Basin. Contamination is relatively wide-spread throughout these headwaters tributaries, ranging from tributaries of the Eagle, the Gunnison, the Animas, the East, and the Dolores Rivers; however, contamination rarely travels far downstream. The metal-rich geology in the Rocky Mountains creates natural background levels of metal contamination, which have then been exacerbated by 150 years of mining activities. Dissolved heavy metals require specific chemical conditions to persist (e.g., low pH) and thus do not often propagate into the mainstem of the Colorado River.		Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated in the headwater tributaries of the Upper Basin. Contamination is relatively wide-spread throughout these headwaters tributaries, ranging from tributaries of the Eagle, the Gunnison, the Animas, the East, and the Dolores Rivers; however, contamination rarely travels far downstream. The metal-rich geology in the Rocky Mountains creates natural background levels of metal contamination, which have then been exacerbated by 150 years of mining activities. Dissolved heavy metals require specific chemical conditions to persist (e.g., low pH) and thus do not often propagate into the mainstem of the Colorado River.

	[[File:~~Earp_moreo_reservoirEvap~~.~~png~~\|thumb\|700px\|Figure 1: The mixing zone of the Animas River (left) and Cement Creek (right). Water in Cement Creek is metal-rich, low-pH while water in the Animas River has low metal concentrations and near-neutral pH. The dilution of Cement Creek in the Animas River increases the pH of Cement Creek water, leading many of the dissolved metals to precipitate back into solid form, from solution. (Photo credit: U.S. Geological Survey). ]]		[[File:AnimasMixingZone.jpeg\|thumb\|700px\|Figure 1: The mixing zone of the Animas River (left) and Cement Creek (right). Water in Cement Creek is metal-rich, low-pH while water in the Animas River has low metal concentrations and near-neutral pH. The dilution of Cement Creek in the Animas River increases the pH of Cement Creek water, leading many of the dissolved metals to precipitate back into solid form, from solution. (Photo credit: U.S. Geological Survey). ]]

	Sulfide-rich minerals, such as pyrite, react with oxygen and water to form sulfuric acid. The sulfuric acid can then leach metals from surrounding host rock and these dissolved metals can travel downstream. Most metals are soluble only at acidic pH meaning that these metals precipitate back into solid form at near-neutral pH; most metal-rich acidic waters are attenuated at confluences with cleaner streams that have higher pH.		Sulfide-rich minerals, such as pyrite, react with oxygen and water to form sulfuric acid. The sulfuric acid can then leach metals from surrounding host rock and these dissolved metals can travel downstream. Most metals are soluble only at acidic pH meaning that these metals precipitate back into solid form at near-neutral pH; most metal-rich acidic waters are attenuated at confluences with cleaner streams that have higher pH.

TanyaPetach at 17:48, 15 May 2023

2023-05-15T17:48:20Z

← Older revision		Revision as of 13:48, 15 May 2023
Line 6:		Line 6:

	Sulfide-rich minerals, such as pyrite, react with oxygen and water to form sulfuric acid. The sulfuric acid can then leach metals from surrounding host rock and these dissolved metals can travel downstream. Most metals are soluble only at acidic pH meaning that these metals precipitate back into solid form at near-neutral pH; most metal-rich acidic waters are attenuated at confluences with cleaner streams that have higher pH.		Sulfide-rich minerals, such as pyrite, react with oxygen and water to form sulfuric acid. The sulfuric acid can then leach metals from surrounding host rock and these dissolved metals can travel downstream. Most metals are soluble only at acidic pH meaning that these metals precipitate back into solid form at near-neutral pH; most metal-rich acidic waters are attenuated at confluences with cleaner streams that have higher pH.
	Mining activities often increase the surface area of sulfide minerals that are in contact with oxygen and water. Metal leaching due to mining-exacerbated sulfide weathering is referred to as acid mine drainage and is a major contributor to dissolved metals in headwater streams i. Much of the contamination from acid mine drainage in the headwaters of the Colorado River has persisted for decades and is likely to continue given the complexity of the situation. Limited cleanup funding, legal constraints surrounding the Superfund program, antiquated mining laws, mixed land-ownership, tenuous good-samaritan laws, and the perpetual nature of sulfide oxidation have limited the extent of mitigation. In particular, once surface disturbances cause additional sulfide minerals to be exposed to oxygen and water, stopping that sulfide oxidation is difficult, and solutions are costly.		Mining activities often increase the surface area of sulfide minerals that are in contact with oxygen and water. Metal leaching due to mining-exacerbated sulfide weathering is referred to as acid mine drainage and is a major contributor to dissolved metals in headwater streams. Much of the contamination from acid mine drainage in the headwaters of the Colorado River has persisted for decades and is likely to continue given the complexity of the situation. Limited cleanup funding, legal constraints surrounding the Superfund program, antiquated mining laws, mixed land-ownership, tenuous good-samaritan laws, and the perpetual nature of sulfide oxidation have limited the extent of mitigation. In particular, once surface disturbances cause additional sulfide minerals to be exposed to oxygen and water, stopping that sulfide oxidation is difficult, and solutions are costly.

	Acid mine drainage in the Colorado River Basin gained notoriety following the Gold King Mine Spill in 2015 in Cement Creek, a tributary to the Animas River, which flows into the San Juan River and the Colorado River. During the Gold King Mine Spill, 3 million gallons of acid mine drainage were accidentally released following remediation efforts on a collapsed mine tunnel. Abandoned mines continuously leach acid mine drainage into Cement Creek and the spill volume was equivalent to the volume of acid mine drainage typically leaked in less than a week. However, since the spill happened abruptly, the acid mine drainage plume had severely concentrated metals and traveled farther downstream the Animas River than usual and the precipitating iron turned the stream a vibrant and disturbing orange color. The spill resulted in extensive litigation between the states of Colorado, New Mexico, Utah, and Navajo Nation; following the Gold King Mine spill, the region was designated as an EPA superfund site.		Acid mine drainage in the Colorado River Basin gained notoriety following the Gold King Mine Spill in 2015 in Cement Creek, a tributary to the Animas River, which flows into the San Juan River and the Colorado River. During the Gold King Mine Spill, 3 million gallons of acid mine drainage were accidentally released following remediation efforts on a collapsed mine tunnel. Abandoned mines continuously leach acid mine drainage into Cement Creek and the spill volume was equivalent to the volume of acid mine drainage typically leaked in less than a week. However, since the spill happened abruptly, the acid mine drainage plume had severely concentrated metals and traveled farther downstream the Animas River than usual and the precipitating iron turned the stream a vibrant and disturbing orange color. The spill resulted in extensive litigation between the states of Colorado, New Mexico, Utah, and Navajo Nation; following the Gold King Mine spill, the region was designated as an EPA superfund site.

TanyaPetach at 17:47, 15 May 2023

2023-05-15T17:47:50Z

← Older revision		Revision as of 13:47, 15 May 2023
Line 23:		Line 23:
	==Additional resources==		==Additional resources==

	===Colorado Abandoned Mines Water Quality Study===		===[https://erams.com/catena/wp-content/uploads/2020/01/Abandoned-Mine-Water-Quality-Study_06-01-17.pdf Colorado Abandoned Mines Water Quality Study]===
	The Colorado Department of Natural Resources surveyed and sampled 145 abandoned mine sites with actively discharging water. These data are presented in a [https://erams.com/catena/wp-content/uploads/2020/01/Abandoned-Mine-Water-Quality-Study_06-01-17.pdf 2017 report].		The Colorado Department of Natural Resources surveyed and sampled 145 abandoned mine sites with actively discharging water. These data are presented in a [https://erams.com/catena/wp-content/uploads/2020/01/Abandoned-Mine-Water-Quality-Study_06-01-17.pdf 2017 report].

TanyaPetach: Created page with "==Overview== Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated i..."

2023-05-15T17:47:08Z

Created page with "==Overview== Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated i..."

New page

==Overview==

Heavy metal contamination in the Colorado River (including dissolved and particulate zinc, cadmium, lead, arsenic, copper, and iron) is primarily concentrated in the headwater tributaries of the Upper Basin. Contamination is relatively wide-spread throughout these headwaters tributaries, ranging from tributaries of the Eagle, the Gunnison, the Animas, the East, and the Dolores Rivers; however, contamination rarely travels far downstream. The metal-rich geology in the Rocky Mountains creates natural background levels of metal contamination, which have then been exacerbated by 150 years of mining activities. Dissolved heavy metals require specific chemical conditions to persist (e.g., low pH) and thus do not often propagate into the mainstem of the Colorado River.

[[File:Earp_moreo_reservoirEvap.png|thumb|700px|Figure 1: The mixing zone of the Animas River (left) and Cement Creek (right). Water in Cement Creek is metal-rich, low-pH while water in the Animas River has low metal concentrations and near-neutral pH. The dilution of Cement Creek in the Animas River increases the pH of Cement Creek water, leading many of the dissolved metals to precipitate back into solid form, from solution. (Photo credit: U.S. Geological Survey). ]]

Sulfide-rich minerals, such as pyrite, react with oxygen and water to form sulfuric acid. The sulfuric acid can then leach metals from surrounding host rock and these dissolved metals can travel downstream. Most metals are soluble only at acidic pH meaning that these metals precipitate back into solid form at near-neutral pH; most metal-rich acidic waters are attenuated at confluences with cleaner streams that have higher pH.
Mining activities often increase the surface area of sulfide minerals that are in contact with oxygen and water. Metal leaching due to mining-exacerbated sulfide weathering is referred to as acid mine drainage and is a major contributor to dissolved metals in headwater streams i. Much of the contamination from acid mine drainage in the headwaters of the Colorado River has persisted for decades and is likely to continue given the complexity of the situation. Limited cleanup funding, legal constraints surrounding the Superfund program, antiquated mining laws, mixed land-ownership, tenuous good-samaritan laws, and the perpetual nature of sulfide oxidation have limited the extent of mitigation. In particular, once surface disturbances cause additional sulfide minerals to be exposed to oxygen and water, stopping that sulfide oxidation is difficult, and solutions are costly.

Acid mine drainage in the Colorado River Basin gained notoriety following the Gold King Mine Spill in 2015 in Cement Creek, a tributary to the Animas River, which flows into the San Juan River and the Colorado River. During the Gold King Mine Spill, 3 million gallons of acid mine drainage were accidentally released following remediation efforts on a collapsed mine tunnel. Abandoned mines continuously leach acid mine drainage into Cement Creek and the spill volume was equivalent to the volume of acid mine drainage typically leaked in less than a week. However, since the spill happened abruptly, the acid mine drainage plume had severely concentrated metals and traveled farther downstream the Animas River than usual and the precipitating iron turned the stream a vibrant and disturbing orange color. The spill resulted in extensive litigation between the states of Colorado, New Mexico, Utah, and Navajo Nation; following the Gold King Mine spill, the region was designated as an EPA superfund site.

==Relevance==
Metal contamination in headwater tributaries typically impacts local communities on these smaller streams; the Gold King Mine Spill was a notable exception. While metal contamination is insidious and poses many challenges to clean up efforts, extensive efforts are ongoing. Clean-up work carried out by the EPA, nonprofits, state and local organizations has improved metal concentrations in many reaches of headwaters streams in the Upper Colorado River. However, these improvements are complicated by continued sulfide mineral oxidation at abandoned mine sites and at modern mines continues to contribute metal contamination to headwater streams.

==Data and tools==
<onlyinclude>
===[https://mrdata.usgs.gov/catalog/science.php?thcode=2&term=1724 USGS abandoned mine water quality database]===
The USGS abandoned mine and water quality database is hosted by the USGS and houses USGS publications, data releases, and relevant reports pertaining to the introduction of harmful substances into the environment from mines and tailings.

===[https://www.epa.gov/data EPA water quality database]===
The EPA reports and releases relevant data from acid mine drainage sites at which the EPA is involved. [https://www.epa.gov/goldkingmine/test2-data-gold-king-mine-response Specific pages] host data specifically relevant to the Gold King Mine spill (2015).

==Additional resources==

===Colorado Abandoned Mines Water Quality Study===
The Colorado Department of Natural Resources surveyed and sampled 145 abandoned mine sites with actively discharging water. These data are presented in a [https://erams.com/catena/wp-content/uploads/2020/01/Abandoned-Mine-Water-Quality-Study_06-01-17.pdf 2017 report].