NOTE 18 FAIR VALUE MEASUREMENTS

(a) Fair Value Hierarchy

Under ASC 820, Fair Value Measurements and Disclosures, fair value measurements are characterized in one of three levels based upon the input used to arrive at the measurement. The three levels of the fair value hierarchy are as follows:


•	Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access at the measurement date.
•	Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.
•	Level 3 inputs are unobservable inputs for the asset or liability.

When appropriate, valuations are adjusted for various factors including credit considerations. Such adjustments are generally based on available market evidence. In the absence of such evidence, management's best estimate is used.

(b) Fair Value of Financial Instruments

The carrying value of cash and cash equivalents, accounts receivable and other, accounts payable and accrued liabilities, accounts payable to affiliates, accrued interest and short-term debt approximate their fair values because of the short maturity or duration of these instruments, or because the instruments bear a variable rate of interest or a rate that approximates current rates. The fair value of the Partnership's long-term debt is estimated by discounting the future cash flows of each instrument at estimated current borrowing rates. The fair value of interest rate derivatives is calculated using the income approach which uses period-end market rates and applies a discounted cash flow valuation model.

The estimated fair value of the Partnership's debt as at December 31, 2015 and 2014 are as follows:

	2015		2014
December 31 (millions of dollars)	Carrying Value	Fair Value	Carrying Value	Fair Value

Senior Credit Facility due 2017	200	200	330	330
2013 Term Loan Facility due 2018	500	500	500	500
Short-Term Loan Facility due 2015	–	–	170	170
2015 Term Loan Facility due 2018	170	170	–	–
4.65% Unsecured Senior Notes due 2021	350	338	350	375
4.375% Unsecured Senior Notes due 2025	349	314	–	–
5.09% Unsecured Senior Notes due 2015	–	–	75	76
5.29% Unsecured Senior Notes due 2020	100	108	100	111
5.69% Unsecured Senior Notes due 2035	150	151	150	168
Unsecured Term Loan Facility due 2019	75	75	–	–
3.82% Series D Senior Notes due 2017	16	17	20	21

	1,910	1,873	1,695	1,751

Long-term debt is recorded at amortized cost and classified in Level II of the fair value hierarchy for fair value disclosure purposes. Interest rate derivative assets and liabilities are classified in Level II for all periods presented where the fair value is determined by using valuation techniques that refer to observable market data or estimated market prices.

Market risk is the risk that changes in market interest rates may result in fluctuations in the fair values or cash flows of financial instruments. The Partnership's floating rate debt is subject to LIBOR benchmark interest rate risk. The Partnership uses interest rate derivatives to manage its exposure to interest rate risk. We regularly assess the impact of interest rate fluctuations on future cash flows and evaluate hedging opportunities to mitigate our interest rate risk.

The Partnership hedged interest payments on $150 million of our $500 million variable-rate 2013 Term Loan Facility with interest rate swaps effective September 3, 2013 and maturing July 1, 2018, at a weighted average fixed interest rate of 2.79 percent. The interest rate swaps are structured such that the cash flows of the derivative instruments match those of the variable rate of interest on the 2013 Term Loan Facility. At December 31, 2015 and 2014, the fair value of the interest rate swaps accounted for as cash flow hedges was a liability of $1 million (both on a gross and net basis) (December 31, 2013 – less than $1 million). In 2015, the Partnership did not record any amounts in net income related to ineffectiveness for interest rate hedges. The change in fair value of interest rate derivative instruments recognized in other comprehensive income was nil million for the year ended December 31, 2015 (2014 – $1 million; 2013 – less than $1 million). In 2015, the net realized loss related to the interest rate swaps was $2 million and was included in financial charges and other (2014 – $2 million; 2013 – $1 million).

The Partnership has no master netting agreements, however, contracts contain provisions with rights of offset. The Partnership has elected to present the fair value of derivative instruments with the right to offset on a gross basis in the balance sheet. Had the Partnership elected to present these instruments on a net basis, there would be no effect on the consolidated balance sheet as of December 31, 2015 and 2014.

Counterparty credit risk represents the financial loss that the Partnership would experience if a counterparty to a financial instrument failed to meet its obligations in accordance with the terms and conditions of the financial instruments with the Partnership. Our maximum counterparty credit exposure with respect to financial instruments at the balance sheet date consists primarily of the carrying amount, which approximates fair value, of non-derivative financial assets, such as accounts receivable, as well as the fair value of derivative financial assets. We review our accounts receivable regularly and record allowances for doubtful accounts using the specific identification method. At December 31, 2015, we had not incurred any significant credit losses and had no significant amounts past due or impaired. At December 31, 2015 and 2014, the Partnership's maximum counterparty credit exposure consisted of accounts receivable of $35 million.

As discussed more fully in Note 4, we recognized $199 million impairment to our equity investment in Great Lakes during the fourth quarter of 2015, reflected as Impairment of equity-method investment on our Statement of Income for the year ended December 31, 2015. The estimated fair value measurement of this investment is classified as Level 3. In the determination of the fair value, we used an income and market approach based on internal forecasts on expected future cash flows and applied appropriate discount rates. The determination of expected future cash flows involved significant assumptions and estimates regarding revenue, operating and maintenance costs and future growth capital.