as a result of lower crude oil prices could result in a reduction in our borrowing base, which would reduce the amount of financial resources available to meet our operating requirements. If, under certain circumstances, our available capacity under our revolving credit facility falls below certain threshold amounts, or a default or event of default exists, then our cash balances in a dominion account established with the administrative agent will be applied on a daily basis to our outstanding obligations under our revolving credit facility. In addition, decreases in the price of crude oil or increases in crack spreads may require us to post substantial amounts of cash collateral to our hedging counterparties in order to maintain our derivative instruments. If, due to our financial condition or other reasons, the borrowing base under our revolving credit facility decreases, we are limited in our ability to issue letters of credit or we are required to post substantial amounts of cash collateral to our hedging counterparties, our liquidity, financial condition and our ability to make payments on our debt obligations could be materially and adversely affected.
We depend on certain third-party pipelines for transportation of feedstocks and products, and if these pipelines become unavailable to us, our revenues and cash available for payment of our debt obligations could decline.
Our Shreveport facility is interconnected to a pipeline that supplies a portion of its crude oil and a pipeline that ships a portion of its refined fuel products to customers, such as pipelines operated by subsidiaries of Enterprise Products Partners L.P. and Plains. Our Great Falls facility receives crude oil through the Front Range pipeline system via the Bow River Pipeline in Canada. Since we do not own or operate any of these pipelines, their continuing operation is not within our control. The unavailability of any of these third-party pipelines for the transportation of crude oil or our refined fuel products, because of acts of God, accidents, earthquakes or hurricanes, government regulation, terrorism or other third-party events, could lead to disputes or litigation with certain of our suppliers or a decline in our sales, net income and cash available for payments of our debt obligations.
The price volatility of utility services may result in decreases in our earnings, profitability and cash flows.
The volatility in costs of natural gas and other utility services, principally electricity, used by our facilities and other operations affect our net income and cash flows. Natural gas and utility prices are affected by factors outside of our control, such as supply and demand in both local and regional markets. Natural gas prices have historically been volatile.
For example, daily prices for natural gas as reported on the NYMEX ranged between $5.87 and $2.45 per million British thermal unit (“MMBtu”) during the nine months ended September 30, 2021, and between $3.35 and $1.48 per MMBtu during the year ended December 31, 2020. Typically, electricity prices fluctuate with natural gas prices. Future increases in natural gas and utility prices may have a material adverse effect on our results of operations. However, international natural gas prices have been more volatile, and more expensive, than domestic prices, which can provide a competitive advantage to domestic plants. This dynamic means that market product prices may increase more than our utility costs, creating higher margins when natural gas and utility costs increase less than international competitors’ utility prices. Natural gas and utility costs constituted approximately 10.8% and 10.1% of our total operating expenses included in cost of sales for the nine months ended September 30, 2021 and the year ended December 31, 2020, respectively. As prices and industry competitive dynamics change, it could adversely affect our profitability and the amount of cash available for payments of our debt obligations.
Our facilities incur operating hazards, and the potential limits on insurance coverage could expose us to potentially significant liability costs.
Our facilities are subject to certain operating hazards, and our cash flow from those operations could decline if any of our facilities experience a major accident, pipeline rupture or spill, explosion or fire, is damaged by severe weather or other natural disaster, or otherwise is forced to curtail its operations or shut down. These operating hazards could result in substantial losses due to personal injury and/or loss of life, severe damage to and destruction of property and equipment, and pollution or other environmental damage. One or more of these developments may result in significant curtailment or suspension of our related operations.
Although we maintain insurance policies, including personal and property damage and business interruption insurance for each of our facilities, we cannot ensure that this insurance will be adequate to protect us from all material expenses related to potential future claims for personal and property damage or significant interruption of operations. Our business interruption insurance will not apply unless a business interruption exceeds 60 days. Furthermore, we may be unable to maintain or obtain insurance of the type and amount we desire at reasonable rates. As a result of market conditions, premiums and deductibles for certain of our insurance policies have increased and could escalate further. In some instances, certain insurance could become unavailable or available only for reduced amounts of coverage. In addition, we are not fully insured against all risks incident to our business because certain risks are not fully insurable, coverage is unavailable, or premium costs, in our judgment, do not justify such expenditures. For example, we are not insured for all environmental liabilities, including, but not limited to, product spills and other releases at all of our facilities. If we were to incur a significant liability for which we are not insured or fully insured, it could affect our financial condition and diminish our ability to make payments of our debt obligations.
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