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Presented at the Mining, Forest & Land Restoration Symposium/workshop July, 2000 Sponsored by the the Rocky Mountain Water Environment Association Biosolids Committee. Land Restoration at the Climax Mine. Zach Margolis. Project Overview.
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Presented at the Mining, Forest & Land Restoration Symposium/workshop July, 2000 Sponsored by thethe Rocky Mountain Water Environment Association Biosolids Committee Land Restoration at the Climax Mine Zach Margolis
Project Overview • The application of biosolids is an important part of the re-vegetation of the tailings ponds at the Climax Mine. • The Summit County biosolids producers are all signatory to an agreement to provide the needed product. • More than 20,000 cubic yards of locally generated wood chips (made from waste forest products and wood from the mine site) are also being used.
Climax Mine History • Molybdenum discovered about 1900 • Production started during WW1 • Uses include • Steel alloying • Lubricants • Dyes • Catalyst in oil refining • Heat sinks on computer processors • Fire retardant • Vitamins
Climax Tailings Ponds Special Challenges Elevation 11,000’ Growing Season 6 weeks Annual Snowfall 23 feet Acres to Turn Green 3000 Tailings pH 3
Climax Mine Restoration “Some of the features of this project appear to be expensive and possibly not justified from a strictly engineering or cost standpoint. As it was the company policy to guard against stream pollution, in case of doubt on any detail the way was chosen which it was thought would give the highest degree of safety” Climax Engineering Report, 1932
Climax Mine Restoration • Tailings production and other disturbances have resulted in the need to restore about 3000 acres. • The company’s use of biosolids to restore the Urad mine 20 years ago was a pioneering use of biosolids for high altitude re-vegetation.
Climax Mine Restoration Experience Urad/Henderson site
An actual photo of Summit County as it appears today. Summit County History • Most of the towns of summit county were born in the gold boom days of the 1800s. • Explosive growth due to tourism and skiing industry development in this environmentally sensitive area has resulted in the production of large quantities of biosolids to be recycled. • Our climate is ideal for skiing but presents a tremendous challenge for reclamation efforts.
Summit County Biosolids RecyclingWhy Mined Land Restoration? • Large areas of flat ground, needed for biosolids application, are hard to find in the mountains. • Based on initial application rates and future maintenance rates this should be a “forever” program. • This is already a restricted access site with contained runoff. • The site is in need of the benefits that biosolids provide.
Mined Land Restoration Using Biosolids. Is There a Downside for the Biosolids Producers? • CERCLA – The Comprehensive Environmental Response, Compensation and Liability Act - aka Superfund • Grade “A” is exempted when it is part of “the normal application of fertilizer”. • Grade “B” ??? No specific exemption …yet.
Weighing the Risks. Aside from possible superfund site designation? • No public distribution of the biosolids, reduced possibility of future public contact.
Weighing the Risks. • Even if we were someday named a “potentially responsible party” our few thousand tons of biosolids won't be significant compared to their billion tons of tailings… we hope. • Still, the Joint Authority decided to not participate in the application of grade “B” biosolids.
What We Are Doing: • There are three different programs: • Direct application of grade “B”
What We Are Doing • Grade “B”/ wood chip blend application
What We Are Doing: • Grade “A” production via composting and subsequent application
Site Preparation and Application • Tails were capped with overburden saved for that purpose. • Surface pH is adjusted with lime. • Biosolids / blends are applied at 20 dry tons of biosolids per acre. • Surface is broadcast seeded.
Results! Last year’s application • The restoration project is working This year’s application
Results! • The restoration project is working 1998’s application
Westvac Environmental Services Inc. • Local contractor provides: • Biosolids hauling to the mine site • Wood chip hauling to the mine site • Biosolids/woodchip blending • Composting at the mine site FOR MORE INFO... Dave Olsen 970-468-4704
Composting The importance of information is directly proportional to It’s improbability. Fundamental Theorem of Information Theory.
One of Our Aerated Static Pile Compost Piles Is a 5 Dry Ton Digester. Electricity Savings: Composting requires 1/250 of the electricity to turn secondary sludge in to grade “A” biosolids compared to what an aerobic digester uses to make grade “B”. Power consumption is about 4500 kilowatt hours per dry ton for the aerobic digester vs. 18 kwh/dt for the aerated static pile. Capital Cost: Assuming a 40 year life on a digester, and a 40 day detention time to produce grade “B” biosolids at 1.5% solids, capital cost is about $44 / dry ton processed. This is comparable to the cost of mixing and piping an aerated static pile.
Composting at a Mine Reclamation Site The case for composting at Climax Mine: • Wood chips were already part of the grade “B” program. • Mixing and mixing equipment were to be on site as part of the program.
The Benefit of the Composting Program to the Silverthorne/Dillon Joint Authority Construction of a 900,000 gallon digester, designed and scheduled for construction in 1996, was postponed indefinitely. By only applying the highest grade biosolids product, to a restricted access site, where all water from that site later passes an NPDES permitted point of compliance, we are minimizing our long term risk, saving energy, and having fun.
Example of Wastewater Plant Operator Having Fun… Writing Letters to Lori Tucker.
Net-ography • biosolids.info.com/regs.htm • cdphe.state.co.us • Compliance bulletin - solid waste certificate of designation as a solid waste disposal site • Proposed solid waste rule changes – composting