PART I—FINANCIAL INFORMATION

See accompanying notes to condensed combined consolidated financial statements.

See accompanying notes to condensed combined consolidated financial statements .  

See accompanying notes to condensed combined consolidated financial statements.

See accompanying notes to condensed combined consolidated financial statements.  

(1) Business and Organization

Antero Midstream Partners LP (the “Partnership”) is a growth-oriented limited partnership formed by Antero Resources Corporation (“Antero”) to own, operate and develop midstream assets to service Antero’s natural gas ,   natural gas liquids (“NGLs”) and oil production .  On November 10, 2014, the Partnership completed its initial public offering (the “IPO”) of 46,000,000 common units representing limited partnership interests at a price of $25.00 per common unit.  The Partnership was originally formed as Antero Resources Midstream LLC and converted to a limited partnership in connection with the completion of the IPO.  At the closing of the IPO, Antero contributed substantially all of its high and low pressure gathering and compression assets to Antero Midstream LLC (“Midstream Operating”), and the equity interests of Midstream Operating were contributed to the Partnership. Our condensed combined consolidated financial statements as of September 30, 2015, include the accounts of the Partnership, Midstream Operating, Antero Water LLC Predecessor (“Antero Water”), and Antero Treatment LLC P redecessor (“Antero Treatment”), all of which are entities under common control.

On September  17 , 2015, the P artnership and Antero Treatment entered into the Contribution Agreement . Pursuant to the terms of the Contribution Agreement, Antero agreed to contribute (i) all of the outstanding limited liability company interests of Antero Water to the Partnership and (ii) all of the assets, contracts, rights, permits and properties owned or leased by Antero and used primarily in connection with the construction, ownership, operation, use or maintenance of Antero’s advanced wastewater treatment complex to be constructed in Doddridge County, West Virginia, to Antero Treatment .   In consideration for the contribution of the Contributed Assets, the Partnership (i) paid Antero a cash distribution equal to $552.5 million, less $171 million of assumed debt, (ii) issued 10,988,421 common units representing limited partner interests in the Partnership to Antero and distributed proceeds of approximately $241 million from the Partnership’s private placement of common units to a group of institutional investors and (iii) has agreed to pay Antero (a)  $125 million in cash if the Partnership delivers   176,295,000 barrels or more of fresh water during the period between January 1, 2017 and December 31, 2019 and (b) an additional $125 million in cash if the Partnership delivers   219,200,000 barrels or more of fresh water during the period between January 1, 2018 and December 31, 2020.

Also on September 23, 2015, the Partnership completed the previously announced sale of 12,898,000 common units at $18.84 per common unit for net proceeds of approximately $240.2 million (the “ Private Placement ”). The Partnership used a portion of the net proceeds of the Private Placement to repay indebtedness assumed from Antero and to partially fund the Water Acquisition. 

Our gathering and compression assets consist of 8-, 12-, 16-, and 20-inch high and low pressure gathering pipelines and compressor stations that collect natural gas , NGLs and oil from Antero’s wells in the Marcellus Shale in West Virginia and the Utica Shale in Ohio. Our assets also include two independent fresh water distribution systems that deliver water   used by Antero for hydraulic fracturing activities in Antero’s operating areas. The fresh water distribution systems consist of permanent buried pipelines, surface pipelines and fresh water storage facilitates, as well as pumping stations and impoundments to transport the fresh water throughout the pipeline system.

We have a right to participate for up to a 15% non-operating equity interest in an unnamed 50 -mile regional gathering pipeline extension (the “Regional Gathering System”) that will expire six months following the date on which the Regional Gathering System is placed into service. In addition, we have entered into a right-of-first-offer agreement with Antero to allow for us to provide Antero with gas processing or NGLs fractionation, transportation or marketing services in the future.

(2) Summary of Significant Accounting Policies

(a) Basis of Presentation

These condensed combined consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) applicable to interim financial information, and should be read in the context of the December 31, 2014 consolidated financial statements and notes thereto for a more complete understanding of the Partnership’s operations, financial position, and accounting policies.  The December 31, 2014 consolidated financial statements were originally filed with the SEC in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2014 and were subsequently recast to include the historical results of Antero Water.  The recast December 31, 2014 combined consolidated financial statements were filed with the SEC as Exhibit 99.1 to the Partnership’s Current Report on Form 8-K filed October 9, 2015.

The accompanying unaudited condensed combined consolidated financial statements of the Partnership have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information, and, accordingly, do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. In the opinion of management, these statements include all adjustments (consisting of normal and recurring accruals) considered necessary for a fair presentation of the Partnership’s financial position as of December 31, 2014 and September 30, 2015, the results of its operations for the three and nine months ended September 30, 2014 and 2015 and its cash flows for the nine months ended September 30, 2014 and 2015. The Partnership has no items of other comprehensive income or loss; therefore, its net income is identical to its comprehensive income. Operating results for the period ended September 30, 2015 are not necessarily indicative of the results that may be expected for the full year.

The accompanying condensed combined consolidated financial statements represent the assets, liabilities, and results of operations of Antero’s gathering and compression assets and water handling assets as the accounting predecessor (the “Predecessor”) to the Partnership, presented on a carve-out basis of Antero’s historical ownership of the Predecessor. The Predecessor financial statements have been prepared from the separate records maintained by Antero and may not necessarily be indicative of the actual results of operations that might have occurred if the Predecessor had been operated separately during the periods reported. References in these financial statements to “Predecessor,” “we,” “our,” “us” or like terms, when referring to periods prior to November 10, 2014, refer to Antero’s gathering, compression and water assets, our predecessor for accounting purposes.  References to “the Partnership,” “we,” “our,” “us” or like terms, when referring to periods between November 10, 2014 and September 23, 2015 refer to the Partnership’s gathering and compression assets and Antero’s water assets. References to “ the P artnership ,” “we,” “our,” “us” or like terms, when referring to periods since September 23, 2015 or when used in the present tense or prospectively, refer to the Partnership.

Certain costs of doing business which are incurred by Antero on our behalf have been reflected in the accompanying condensed combined consolidated financial statements. These costs include general and administrative expenses a ttributed to us by Antero in exchange for:

Transactions between us and Antero have been identified in the condensed combined consolidated financial statements as transactions between affiliates (see Note 3).

As of the date these condensed combined consolidated financial statements were filed with the SEC, the Partnership completed its evaluation of potential subsequent events for disclosure and no items requiring disclosure were identified, except the declaration of a cash distribution to unitholders, as described in Note 6—Partnership Equity and Distributions.

(b) Revenue Recognition

We provide gathering and compression and water handling services under fee-based contracts primarily based on throughput. Under these arrangements, we receive fees for gathering oil and gas products and compression services. The revenue we earn from these arrangements is directly related to (1) in the case of natural gas gathering and compression, the volumes of metered natural gas that we gather, compress and deliver to natural gas compression sites or other transmission delivery points (2) in the case of oil and condensate gathering, the volumes of metered oil and condensate that we gather and deliver to other transmission delivery points or (3) in the case of water handling services, the quantities of fresh water delivered to our customers for use in their well completion operations. We recognize revenue when all of the following criteria are met: (1) persuasive evidence of an agreement exists, (2) services have been rendered, (3) prices are fixed or determinable and (4) collectability is reasonable assured.  

(c) Use of Estimates

The preparation of the condensed combined consolidated financial statements and notes in conformity with GAAP requires that management formulate estimates and assumptions that affect revenues, expenses, assets, liabilities and the disclosure of contingent assets and liabilities. Items subject to estimates and assumptions include the useful lives of property and equipment and valuation of accrued liabilities, among others. Although management believes these estimates are reasonable, actual results could differ from these estimates.

In the third quarter, as a result of our review of recent rulings, our estimated ad valorem tax expense was decreased by $8.4 million related to prior periods due to a change in our estimated future tax liability.  This was accounted for as a change in an accounting estimate.  

(d) Cash and Cash Equivalents

Prior to the IPO, the Predecessor’s gathering and compression operations were funded by Antero, and prior to September 23, 2015 Antero Water’s operations were funded by Antero. Net amounts funded by Antero are reflected as net contributions from parent on the accompanying Statements of Condensed Combined Consolidated Cash Flows.

We consider all liquid investments purchased with an initial maturity of three months or less to be cash equivalents. The carrying value of cash and cash equivalents approximates fair value due to the short-term nature of these instruments.

(e) Property and Equipment

Property and equipment primarily consists of gathering pipelines, compressor stations and fresh water distribution pipelines and facilities stated at historical cost less accumulated depreciation. We capitalize construction-related direct labor and material costs. Maintenance and repair costs are expensed as incurred.

Depreciation is computed using the straight-line method over the estimated useful lives and salvage values of assets. The depreciation of fixed assets recorded under capital lease agreements is included in depreciation expense. Uncertainties that may impact these estimates of useful lives include, among others, changes in laws and regulations relating to environmental matters, including air and water quality, restoration and abandonment requirements, economic conditions, and supply and demand for our services in the areas in which we operate. When assets are placed into service, management makes estimates with respect to

useful lives and salvage values that management believes are reasonable. However, subsequent events could cause a change in estimates, thereby impacting future depreciation amounts.

Our investment in property and equipment for the periods presented is as follows:

(f) Impairment of Long ‑Lived Assets

We evaluate our long ‑lived assets for impairment when events or changes in circumstances indicate that the related carrying values of the assets may not be recoverable.  Generally, the basis for making such assessments is undiscounted future cash flow projections for the unit being assessed.  If the carrying values of the assets are deemed not recoverable, the carrying values are reduced to the estimated fair value, which is based on discounted future cash flows or other techniques, as appropriate.  No impairments for such assets have been recorded through September 30, 2015.

(g) Asset Retirement Obligations

Our gathering pipelines, compressor stations and freshwater distribution pipelines and facilities have an indeterminate life, if properly maintained. A liability for these asset retirement obligations will be recorded only if and when a future retirement obligation with a determinable life can be estimated. It has been determined by our operational management team that abandoning all other ancillary equipment, outside of the assets stated above, would require minimal costs. Because we are not able to make a reasonable estimate of when future dismantlement and removal dates of our pipelines, compressor stations and facilities, will occur, and because it has been determined that abandonment of all other ancillary assets would only require minimal costs, we have not recorded asset retirement obligations at December 31, 2014 or September 30, 2015.

(h) Litigation and Other Contingencies

An accrual is recorded for a loss contingency when its occurrence is probable and damages can be reasonably estimated based on the anticipated most likely outcome or the minimum amount within a range of possible outcomes. We regularly review contingencies to determine the adequacy of our accruals and related disclosures. The ultimate amount of losses, if any, may differ from these estimates.

We accrue losses associated with environmental obligations when such losses are probable and can be reasonably estimated. Accruals for estimated environmental losses are recognized no later than at the time a remediation feasibility study, or an evaluation of response options, is complete. These accruals are adjusted as additional information becomes available or as circumstances change. Future environmental expenditures are not discounted to their present value. Recoveries of environmental costs from other parties are recorded separately as assets at their undiscounted value when receipt of such recoveries is probable.

  (i) Equity ‑Based Compensation

Our condensed combined consolidated financial statements reflect various equity-based compensation awards granted by Antero, as well as compensation expense associated with our own plan. These awards include profits interests awards, restricted stock, stock options, restricted units, and phantom units. For purposes of these condensed combined consolidated financial statements, we recognized as expense in each period an amount allocated from Antero, with the offset included in partners’ capital. See Note 3—Transactions with Affiliates for additional information regarding Antero’s allocation of expenses to us.

In connection with the IPO, our general partner adopted the Antero Midstream Partners LP Long-Term Incentive Plan (“Midstream LTIP”), pursuant to which certain non-employee directors of our general partner and certain officers, employees and consultants of our general partner and its affiliates are eligible to receive awards representing equity interests in the Partnership. An aggregate of 10,000,000 common units may be delivered pursuant to awards under the Midstream LTIP, subject to customary adjustments. For accounting purposes, these units are treated as if they are distributed from us to Antero. Antero recognizes compensation expense for the units awarded to its employees and a portion of that expense is allocated to us. There is no cash paid to Antero for the amount allocated to us. See Note 5—Equity-Based Compensation.

(j) Income Taxes

Our condensed combined consolidated financial statements do not include a provision for income taxes as we are treated as a partnership for federal and state income tax purposes, with each partner being separately taxed on its share of taxable income.

(k) Fair Value Measures

The Financial Accounting Standards Board (the “FASB”) Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosures, clarifies the definition of fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. This guidance also relates to all nonfinancial assets and liabilities that are not recognized or disclosed on a recurring basis (e.g., the initial recognition of asset retirement obligations and impairments of long ‑lived assets). The fair value is the price that we estimate would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A fair value hierarchy is used to prioritize inputs to valuation techniques used to estimate fair value. An asset or liability subject to the fair value requirements is categorized within the hierarchy based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. The highest priority (Level 1) is given to unadjusted quoted market prices in active markets for identical assets or liabilities, and the lowest priority (Level 3) is given to unobservable inputs. Level 2 inputs are data, other than quoted prices included within Level 1, that are observable for the asset or liability, either directly or indirectly.

The carrying values on our balance sheet of our cash and cash equivalents, accounts receivable—affiliate, accounts receivable—third party, prepaid expenses, other assets, accounts payable, accounts payable—affiliate, accrued liabilities, accrued capital expenditures, accrued ad valorem tax, other current liabilities, other liabilities and the revolving credit facility approximate fair values due to their short-term maturities.  

As discussed in Note  8 — Fair Value Measurement , the Partnership has agreed to pay Antero contingent consideration in connection with the Water A cquisition. See Note 8—Fair Value Measurement.

(l) Reclassifications   

Certain reclassifications have been made to prior periods’ financial information related to direct operating expenses to conform that information to our current period presentation. These reclassifications did not have an impact on net income for the periods previously reported.

(3) Transactions with Affiliates

(a) Revenues

Gathering and compression revenues earned from Antero were $26.3 million and $59. 2 million during the three months ended September 30, 2014 and 2015, respectively, and $55.0 million and $168. 1 million during the nine months ended September 30, 2014 and 2015, respectively. Water handling revenues earned from Antero were $42.6 million and $21.8 million during the three months ended September 30, 2014 and 2015, respectively, and $107.9 million and $86.8 million during the nine months ended September 30, 2014 and 2015, respectively. 

(b) Accounts receivable—affiliate and Accounts payable—affiliate

Accounts receivable—affiliate represents amounts due from Antero, primarily related to gathering and compression services, water handling services, net working capital receivable attributable to the Water Acquisition and other costs. Accounts payable—affiliate represents amounts due to Antero for general and administrative and other costs.

(c) Accounts Payable, Accrued Expenses, and Accrued Capital Expenditures

All accounts payable, accrued liabilities and accrued capital expenditures balances are due to transactions with unaffiliated parties. Prior to the IPO, all operating and capital expenditures, related to gathering and compression activities were funded through capital contributions from Antero and borrowings under its midstream credit facility. Prior to September 23, 2015, all operating and capital expenditures related to Antero Water were funded through capital contributions from Antero and borrowings under the water credit facility. See Note 4 — Long-term Debt. These balances were managed and paid under Antero’s cash management program. Following the IPO, we maintained our own bank accounts and sources of liquidity related to gathering and compression operations, and on September 23, 2015, we began to maintain our own bank accounts and sources of liquidity for water handling operations.

(d) Allocation of Costs

The employees supporting our operations are employees of Antero. Direct operating expense includes allocated costs of $0.5 million and $ 0.8 million during the three months ended September 30, 2014 and 2015, respectively, and $ 1.1 million and $2.2 million during the nine months ended September 30, 2014 and 2015, respectively, related to direct labor charges for Antero employees associated with the operation of our gathering lines and compressor stations. General and administrative expense includes allocated costs of $ 7.4 million and $ 11. 6 million during the three months ended September 30, 2014 and 2015, respectively, and $ 20.9 million and $ 33.9 million during the nine months ended September 30, 2014 and 2015, respectively. These costs relate to: (i) various business services, including payroll processing, accounts payable processing and facilities management, (ii) various corporate services, including legal, accounting, treasury, information technology and human resources and (iii) compensation, including equity ‑based compensation (see Note 5—Equity-Based Compensation for more information). These expenses are charged or allocated to us based on the nature of the expenses and are allocated based on a combination of our proportionate share of Antero’s gross property and equipment, capital expenditures and direct labor costs, as applicable.

(e) Water Acquisition

In the third quarter of 2015 we acquired Antero’s water handling business in exchange for a combination of cash and equity consideration. See Note 1—Business and Organization.

(4) Long-Term Debt

(a) Revolving Credit Facility

On November 10, 2014, in connection with the closing of the IPO, the Partnership entered into a revolving credit facility with a syndicate of bank lenders (the “revolving credit facility”). The revolving credit facility initially provide d for lender commitments of $1.0 billion and a letter of credit sublimit of $150  million. The revolving credit facility will mature on November 10, 2019.

The revolving credit facility is ratably secured by mortgages on substantially all of our properties, including the properties of our restricted subsidiaries, and guarantees from our restricted subsidiaries. The revolving credit facility contains certain covenants including restrictions on indebtedness and distributions, and requirements with respect to leverage and interest coverage ratios. The Partnership was in compliance with all of the financial covenants under the revolving credit facility as of December 31, 2014 and September 30, 2015.

Principal amounts borrowed are payable on the maturity date with such borrowings bearing interest that is payable quarterly or, in the case of Eurodollar Rate Loans, at the end of the applicable interest period if shorter than three months. Interest is payable at a variable rate based on LIBOR or the base rate, determined by election at the time of borrowing. Commitment fees on the unused portion of the revolving credit facility are due quarterly at rates ranging from 0.25% to 0.375% of the unused facility based on utilization.

At December 31, 2014 and September 30, 2015, we had borrowings under the revolving credit facility of zero and $525 million, respectively, with a weighted average interest rate of 1.70% and no letters of credit outstanding at December 31, 2014 or September 30, 2015.

On September 23, 2015, aggregate lender commitments under the revolving credit facility increased to $1.5 billion in connection with the Water Acquisition.

(b) Midstream Credit Facility

Prior to the closing of the IPO on November 10, 2014, long-term debt represented amounts outstanding under a credit facility agreement between Midstream Operating, then a wholly owned subsidiary of Antero and now a wholly owned subsidiary of the Partnership, and the lenders under Antero’s credit facility (the “Antero credit facility”), that were incurred for the Water Acquisition and construction of the Predecessor’s gathering and compression assets (the “Midstream credit facility”). The facilities were ratably secured by mortgages on substantially all of Antero’s properties, by a security interest on substantially all of Midstream Operating’s personal property and by guarantees from Antero and its restricted subsidiaries. On November 10, 2014, in connection with the completion of the IPO, the outstanding balance of the Midstream credit facility was repaid out of the proceeds of the IPO, and this facility was assumed by Antero Water.

(c) Antero Water Credit Facility

On November 10, 2014, in connection with the closing of the IPO, Antero Water assumed the Midstream credit facility under amended terms (the “Water facility”), in order to provide for separate borrowings attributable to Antero’s water handling business. The Water facility was repaid in full and terminated on September 23, 2015, in connection with the Water Acquisition.

As of December 31, 2014, Antero Water had a total outstanding balance under the Water facility of $115 million, with a weighted average interest rate of 2.19% . Antero was in compliance with all of the financial covenants under the Water facility as of December 31, 2014.

(5) Equity-Based Compensation

Our general and administrative expenses include equity-based compensation costs allocated to us by Antero for grants made pursuant to: (i) the Antero Resources Corporation Long ‑Term Inc entive Plan (the “Antero LTIP”); (ii) profits interests awards valued in connection with the Antero reorganization pursuant to its initial public offeri ng of common stock, which closed on October 16, 2013; and (iii) the Midstream LTIP.  Equity ‑based compensation expense allocated to us was $ 2.1 million and $ 5.3 million for the three months ended September 30 , 2014 and 2015, respectively , and $ 7.4 million and $ 17.7 million for the nine months ended September 30 , 2014 and 2015, respectively . These expenses were allocated to us based on our proportionate share of Antero’s labor costs. Antero has unamortized expense totaling approximately $ 175 million as of September 30 , 2015 related to its various equity-based compensation plans and the Midstream LTIP. A portion of this will be allocated to us as it is amortized over the remaining service period of the related awards.

Midstream LTIP

Our general partner manages our operations and activities and Antero employs the personnel who provide support to our operations. In connection with the IPO, our general partner adopted the Midstream LTIP, pursuant to which non ‑employee directors of our general partner and certain officers, employees and consultants of our general partner and its affiliates are eligible to receive awards   representing ownership interests in the Partnership. An aggregate of 10,000,000 common units may be delivered pursuant to awards under the Midstream LTIP, subject to customary adjustments.  A total of 7,65 8 , 3 63 common units are available for future grant under the Midstream LTIP as of September 30 , 2015.   R estricted units and phantom units granted under the Midstream LTIP vest subject to the satisfaction of service requirements, upon the completion of which common units in the Partnership are delivered to the holder of the restricted units or phantom units. Compensation related to each restricted unit and phantom unit award is recognized on a straight-line basis over the requisite service period of the entire award.  The grant date fair values of these awards are determined based on the closing price of the Partnership’s common units on the date of grant. These units are accounted for as if they are distributed by the Partnership to Antero. Antero recognizes compensation expense for the units awarded and a portion of that expense is allocated to the Partnership . Antero allocates equity- based compensation expense to the Partnership based on our proportionate share of Antero’s direct labor costs. The Partnership’s portion of the equity-based compensation expense is included in general and administrative expenses , and recorded as a credit to the applicable class es of partners’ capital .  

A summary of restricted unit and phantom unit awards activity during the nine months ended September 30 , 2015 is as follows:

Intrinsic values are based on the closing price of the Partnership’s common units on the referenced dates.  Unamortized expense of $5 2 .5 million at September 30 , 2015 is expected to be recognized by Antero over a weighted average period of approximately 3 .1 years. A proportionate share of the expense will be allocated to us as it is recognized by Antero.

(6) Partnership Equity and Distributions

Our Minimum Quarterly Distribution

Our partnership agreement provides for a minimum quarterly distribution of $0.17 per unit for each quarter, or $0.68 per unit on an annualized basis.

Our partnership agreement generally provides that we distribute cash each quarter during the subordination period in the following manner:

If cash distributions to our unitholders exceed $0.1955 per common unit and subordinated unit in any quarter, our unitholders and our general partner, as the holder of our incentive distribution rights (“IDRs”), will receive distributions according to the following percentage allocations:

General Partner Interest

Our general partner owns a non ‑economic general partner interest in us, which does not entitle it to receive cash distributions. However, our general partner owns the IDRs and may in the future own common units or other equity interests in us and will be entitled to receive distributions on any such interests.

Subordinated Units

Antero owns all of our subordinated units. The principal difference between our common units and subordinated units is that, for any quarter during the subordination period, holders of the subordinated units are not entitled to receive any distribution from operating surplus until the common units have received the minimum quarterly distribution from operating surplus for such quarter plus any arrearages in the payment of the minimum quarterly distribution from prior quarters. Subordinated units will not accrue arrearages. When the subordination period ends, all of the subordinated units will convert into an equal number of common units. The subordination period will end on the first business day after we have earned and paid at least $0.68 (the minimum quarterly distribution on an annualized basis) on each outstanding common unit and subordinated unit for each of three consecutive, non-overlapping four-quarter periods ending on or after September 30, 2017 and there are no outstanding arrearages on our common units.

To the extent we do not pay the minimum quarterly distribution on our common units, our common unitholders will not be entitled to receive such arrearage payments in the future except during the subordination period. To the extent we have cash available for distribution from operating surplus in any future quarter during the subordination period in excess of the amount necessary to pay the minimum quarterly distribution to holders of our common units, we will use this excess cash to pay any distribution arrearages on common units related to prior quarters before any cash distribution is made to holders of subordinated units.

Cash Distributions

On October 13, 2015, we announced that the board of directors of our general partner declared a cash distribution of $0.205 per unit for the quarter ended September 30, 2015. The distribution will be payable on November 30, 2015 to unitholders of record as of November 11, 2015.

The following table details the distributions paid during or pertaining to the first nine months of 2015:

(7) Net Income Per Limited Partner Unit

The Partnership’s net income is a ttributed to the general partner and limited partners, including subordinated unitholders, in accordance with their respective ownership percentages, and when applicable, giving effect to incentive distributions paid to the general partner. Basic and diluted net income per limited partner unit is calculated by dividing limited partners’ interest in net income, less general partner incentive distributions, by the weighted average number of outstanding limited partner units during the period.

We compute earnings per unit using the two-class method for master limited partnerships. Under the two-class method, earnings per unit is calculated as if all of the earnings for the period were distributed under the terms of the partnership agreement, regardless of whether the general partner has discretion over the amount of distributions to be made in any particular period, whether those earnings would actually be distributed during a particular period from an economic or practical perspective, or whether the general partner has other legal or contractual limitations on its ability to pay distributions that would prevent it from distributing all of the earnings for a particular period.

We calculate net income available to limited partners based on the distributions pertaining to the current period’s net income. After adjusting for the appropriate period’s distributions, the remaining undistributed earnings or excess distributions over earnings, if any, are a ttributed to the general partner and limited partners in accordance with the contractual terms of the partnership agreement under the two-class method.

Basic earnings per unit is computed by dividing net earnings attributable to unitholders by the weighted average number of units outstanding during each period. Diluted net income per limited partner unit reflects the potential dilution that could occur if agreements to issue common units, such as awards under long-term incentive plans, were exercised, settled or converted into common units. When it is determined that potential common units resulting from an award should be included in the diluted net income per limited partner unit calculation, the impact is reflected by applying the treasury stock method. Earnings per common unit assuming dilution for the three months ended September 30, 2015 was calculated based on the diluted weighted average number of units outstanding of 78,034,156 , including 16,119 dilutive units attributable to non-vested restricted unit and phantom unit awards. Earnings per common unit assuming dilution for the nine months ended September 30, 2015 was calculated based on the diluted weighted average number of units outstanding of 76,657,439 , including 16,514 dilutive units attributable to non-vested restricted unit and phantom unit awards. For the three and nine months ended September 30, 2015, 2,309,580 and 2,314,388 non-vested phantom unit and restricted unit awards, respectively, were anti-dilutive and therefore excluded from the calculation of diluted earnings per unit.

The Partnership’s calculation of net income per common and subordinated unit for the periods indicated is as follows ($ in thousands, except per unit data) :

(8) Fair Value Measurement

In connection with the Water Acquisition , we have agreed to pay Antero (a)  $125 million in cash if the Partnership delivers   176,295,000 barrels or more of fresh water during the period between January 1, 2017 and December 31, 2019 and (b) an additional $125 million in cash if the Partnership delivers   219,200,000 barrels or more of fresh water during the period between January 1, 2018 and December 31, 2020. This contingent consideration liability is valued based on Level 3 inputs.

The following table provides a reconciliation of changes in Level 3 financial liabilities measured at fair value on a recurring basis for the periods shown below (in thousands):

We account for contingent consideration in accordance with applicable accounting guidance pertaining to business combinations. We are contractually obligated to pay Antero contingent consideration in connection with the Water Acquisition, and therefore recorded this contingent consideration liability at the time of the Water Acquisition. We update our assumptions each reporting period based on new developments and adjust such amounts to fair value based on revised assumptions, if applicable, until such consideration is satisfied through payment upon achievement of the specified objectives or it is eliminated upon failure to achieve the specified objectives.

As of September 30, 2015, we are obliga ted to pay these amounts in 2019 and 2020. The fair value measurement is based on significant inputs not observable in the market and thus represents a Level 3 measurement within the fair value hierarchy. The fair value of the contingent consideration liability associated with future milestone payments was based on the risk adjusted present value of the contingent consideration payout.

(9)     Reporting Segments

The Partnership’s operations are located in the United States and are organized into two reporting segments: (1) gathering and compression and (2) water handling.

Gathering and Compression

The gathering and compression segment includes a network of gathering pipelines and compressor stations that collect natural gas, NGLs and oil from Antero’s wells in the Marcellus Shale in West Virginia and the Utica Shale in Ohio.

Water Handling

The Partnership’s water handling segment includes two independent fresh water distribution systems that source and deliver fresh water from the Ohio River and several regional waterways for well completion operations in Antero’s operating areas. These systems consist of permanent buried pipelines, surface pipelines and fresh water storage facilitates, as well as pumping stations and impoundments to transport the fresh water throughout the pipelines. The water handling segment also includes a water treatment facility, currently under construction.

These segments are monitored separately by management for performance and are consistent with internal financial reporting. These segments have been identified based on the differing products and services, regulatory environment and the expertise required for these operations. We evaluate the performance of the Partnership’s business segments based on operating income. Interest expense is primarily managed and evaluated on a consolidated basis.

Summarized financial information concerning the Partnership’s segments for the periods indicated is shown in the following table (in thousands):