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Commitments And Contingencies | 3 Months Ended
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Mar. 31, 2015
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES (a) Capital Purchase Obligations - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects. IPL’s projects include the installation of a scrubber at Lansing Unit 4 to reduce SO2 emissions. WPL’s projects include the installation of a scrubber and baghouse at Edgewater Unit 5 to reduce SO2 and mercury emissions, and generation maintenance and performance improvements at Columbia Units 1 and 2. At March 31, 2015, Alliant Energy’s, IPL’s and WPL’s minimum future commitments related to certain contractual obligations for these projects were $26 million, $2 million and $24 million, respectively. (b) Operating Expense Purchase Obligations - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. Other operating expense purchase obligations with various vendors provide other goods and services. At March 31, 2015, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Purchased power (a): |  |  |  |  |
DAEC (IPL) |  | $1,510 |  |  |  | $1,510 |  |  |  | $— |
Other | 220 |  |  | 1 |  |  | 219 |
| 1,730 |  |  | 1,511 |  |  | 219 |
Natural gas | 228 |  |  | 120 |  |  | 108 |
Coal (b) | 264 |  |  | 113 |  |  | 151 |
SO2 emission allowances | 22 |  |  | 22 |  |  | — |
Other (c) | 39 |  |  | 29 |  |  | 10 |
|  | $2,283 |  |  |  | $1,795 |  |  |  | $488 |
(a) | Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased.
(b) | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of March 31, 2015 regarding expected future usage, which is subject to change.
(c) | Includes individual commitments incurred during the normal course of business that exceeded $1 million at March 31, 2015.
(c) Legal Proceedings - Flood Damage Claims - In June 2013, several plaintiffs purporting to represent a class of residential and commercial property owners filed a complaint against CRANDIC, Alliant Energy and various other defendants in the Iowa District Court for Linn County. Plaintiffs assert claims of negligence and strict liability based on their allegations that CRANDIC (along with other defendants) caused or exacerbated flooding of the Cedar River in June 2008. In July 2013, the case was removed from state court to federal court based on federal jurisdiction. In September 2013, the U.S. District Court for the Northern District of Iowa dismissed the Plaintiffs’ claims and transferred the case for resolution to the Surface Transportation Board, the administrative agency that oversees the Interstate Commerce Commission Termination Act. In October 2013, the Plaintiffs appealed the federal court’s dismissal of the case to the Eighth Circuit Court of Appeals. Alliant Energy and CRANDIC believe the case is without merit and will continue to vigorously contest the case. As a result, Alliant Energy does not currently believe any material losses from these claims are both probable and reasonably estimated, and therefore, has not recognized any material loss contingency amounts for this complaint as of March 31, 2015. Due to the early stages of the claim and the lack of specific damages identified, Alliant Energy is currently unable to provide an estimate of potential loss or range of potential loss. (d) Guarantees and Indemnifications - RMT - In 2013, Alliant Energy sold RMT. RMT provided renewable energy services, including construction and high voltage connection services for wind and solar projects. As part of the sale, Alliant Energy indemnified the buyer for any claims, including claims of warranty under the project obligations that were commenced or are based on actions that occurred prior to the sale, except for liabilities already accounted for through adjustments to the purchase price. The indemnification obligations either cease to exist when the statute of limitation for such claims is met or, in the case of RMT’s projects, when the warranty period under the agreements expires. The warranty periods for RMT’s projects generally range from 12 to 60 months with the latest expiring in 2016. Alliant Energy also continues to guarantee RMT’s performance obligations related to certain of RMT’s projects that were commenced prior to Alliant Energy’s sale of RMT. As of March 31, 2015, Alliant Energy had $251 million of performance guarantees outstanding, with $128 million, $48 million and $75 million currently expected to expire in 2015, 2016 and 2017, respectively. The expiration of these performance guarantees may be extended depending on when all valid warranty claims are resolved for the respective projects. Although Alliant Energy has received warranty claims related to certain of these projects, it does not currently believe that material losses are both probable and reasonably estimated, and therefore, has not recognized any material liabilities related to these matters as of March 31, 2015. Due to the early stages of the warranty claims, Alliant Energy is currently unable to provide an estimate of potential loss or range of potential loss. Whiting Petroleum - In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Whiting Petroleum is an independent oil and gas company. Alliant Energy continues to guarantee the obligations related to the abandonment of certain platforms off the coast of California and related onshore plant and equipment that were owned by Whiting Petroleum prior to Alliant Energy’s sale of Whiting Petroleum. The guarantee does not include a maximum limit. As of March 31, 2015, the present value of the abandonment obligations is estimated at $35 million. Alliant Energy believes that no payments will be made under this guarantee. Alliant Energy has not recognized any material liabilities related to this guarantee as of March 31, 2015. (e) Environmental Matters - MGP Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. IPL and WPL are currently monitoring and/or remediating 25 and 5 sites, respectively. Included in IPL’s sites is a Minnesota site for which responsibility of monitoring and/or remediating the site was transferred to the buyer as part of the sale of IPL’s Minnesota natural gas distribution assets. Environmental liabilities related to these MGP sites are recorded based upon periodic studies. Such amounts are based on the best current estimate of the remaining amount to be incurred for investigation, remediation and monitoring costs for those sites where the investigation process has been or is substantially completed, and the minimum of the estimated cost range for those sites where the investigation is in its earlier stages. There are inherent uncertainties associated with the estimated remaining costs for MGP projects primarily due to unknown site conditions and potential changes in regulatory agency requirements. It is possible that future cost estimates will be greater than current estimates as the investigation process proceeds and as additional facts become known. The amounts recognized as liabilities are reduced for expenditures incurred and are adjusted as further information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted. At March 31, 2015, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Range of estimated future costs |  | $14 |  | - | $34 |  |  | $13 |  | - | $31 |  |  | $1 |  | - | $3
Current and non-current environmental liabilities | 16 |  | 14 |  | 2
WPL Consent Decree - In 2009, the EPA sent a notice of violation to WPL as an owner and the operator of Edgewater, Nelson Dewey and Columbia alleging that the owners of such EGUs failed to comply with appropriate pre-construction review and permitting requirements and as a result violated the PSD program requirements, Title V Operating Permit requirements of the CAA and the Wisconsin State Implementation Plan. In 2010, the Sierra Club filed complaints against WPL, as owner and operator of Nelson Dewey and Columbia, and separately as owner and operator of Edgewater, based on allegations that modifications were made at the facilities without complying with the PSD program requirements, Title V Operating Permit requirements of the CAA and state regulatory counterparts contained within the Wisconsin State Implementation Plan designed to implement the CAA. In April 2013, WPL, along with the other owners of Edgewater and Columbia, entered into a Consent Decree with the EPA and the Sierra Club to resolve the claims relating to Edgewater, Columbia and Nelson Dewey, while admitting no liability. In June 2013, the Consent Decree was approved by the U.S. District Court for the Western District of Wisconsin, thereby resolving all claims against WPL. Under the Consent Decree, WPL is required to install the following emission controls systems:
• | Selective catalytic reduction system at Edgewater Unit 5 by May 1, 2013 (placed in service in 2012);
• | Scrubbers and baghouses at Columbia Units 1 and 2 by December 31, 2014 (placed in service in 2014);
• | Scrubber and baghouse at Edgewater Unit 5 by December 31, 2016; and
• | Selective catalytic reduction system at Columbia Unit 2 by December 31, 2018.
WPL is also required to fuel switch or retire Nelson Dewey Units 1 and 2 and Edgewater Unit 3 by December 31, 2015, and Edgewater Unit 4 by December 31, 2018. In addition, the Consent Decree establishes emission rate limits for SO2, NOx and particulate matter for Columbia Units 1 and 2, Nelson Dewey Units 1 and 2 and Edgewater Units 4 and 5. The Consent Decree also includes annual plant-wide emission caps for SO2 and NOx for Columbia, Edgewater and Nelson Dewey. In addition, WPL will complete approximately $7 million in environmental mitigation projects. Final recovery of the costs expected to be incurred related to the Consent Decree will be decided by the PSCW in future rate cases or other proceedings. Alliant Energy and WPL currently expect to recover any material costs incurred by WPL related to compliance with the terms of the Consent Decree from WPL’s electric customers, except for costs related to certain of the environmental mitigation projects. Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however future capital investments and/or modifications to EGUs to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Clean Air Visibility Rule, MATS Rule, Industrial Boiler and Process Heater Maximum Achievable Control Technology Rule, Ozone National Ambient Air Quality Standards Rule, SO2 National Ambient Air Quality Standards Rule, Federal Clean Water Act including Section 316(b), Effluent Limitation Guidelines, Hydroelectric Fish Passage Device, CCR Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including carbon emissions from new (CAA Section 111(b)) and existing (CAA Section 111(d)) fossil-fueled EGUs. Some recent developments concerning these environmental matters are included below: Air Quality - MATS Rule - In March 2015, the EPA approved an extension to the MATS Rule compliance deadline from April 2015 to April 2016 for IPL’s M.L. Kapp Unit 2. Land and Solid Waste - CCR Rule - Refer to Note 10 for discussion of the final CCR Rule, including additional AROs that are expected to be recognized in the second quarter of 2015.
IPL [Member] |
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES (a) Capital Purchase Obligations - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects. IPL’s projects include the installation of a scrubber at Lansing Unit 4 to reduce SO2 emissions. WPL’s projects include the installation of a scrubber and baghouse at Edgewater Unit 5 to reduce SO2 and mercury emissions, and generation maintenance and performance improvements at Columbia Units 1 and 2. At March 31, 2015, Alliant Energy’s, IPL’s and WPL’s minimum future commitments related to certain contractual obligations for these projects were $26 million, $2 million and $24 million, respectively. (b) Operating Expense Purchase Obligations - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. Other operating expense purchase obligations with various vendors provide other goods and services. At March 31, 2015, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Purchased power (a): |  |  |  |  |
DAEC (IPL) |  | $1,510 |  |  |  | $1,510 |  |  |  | $— |
Other | 220 |  |  | 1 |  |  | 219 |
| 1,730 |  |  | 1,511 |  |  | 219 |
Natural gas | 228 |  |  | 120 |  |  | 108 |
Coal (b) | 264 |  |  | 113 |  |  | 151 |
SO2 emission allowances | 22 |  |  | 22 |  |  | — |
Other (c) | 39 |  |  | 29 |  |  | 10 |
|  | $2,283 |  |  |  | $1,795 |  |  |  | $488 |
(a) | Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased.
(b) | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of March 31, 2015 regarding expected future usage, which is subject to change.
(c) | Includes individual commitments incurred during the normal course of business that exceeded $1 million at March 31, 2015.
(c) Legal Proceedings - Flood Damage Claims - In June 2013, several plaintiffs purporting to represent a class of residential and commercial property owners filed a complaint against CRANDIC, Alliant Energy and various other defendants in the Iowa District Court for Linn County. Plaintiffs assert claims of negligence and strict liability based on their allegations that CRANDIC (along with other defendants) caused or exacerbated flooding of the Cedar River in June 2008. In July 2013, the case was removed from state court to federal court based on federal jurisdiction. In September 2013, the U.S. District Court for the Northern District of Iowa dismissed the Plaintiffs’ claims and transferred the case for resolution to the Surface Transportation Board, the administrative agency that oversees the Interstate Commerce Commission Termination Act. In October 2013, the Plaintiffs appealed the federal court’s dismissal of the case to the Eighth Circuit Court of Appeals. Alliant Energy and CRANDIC believe the case is without merit and will continue to vigorously contest the case. As a result, Alliant Energy does not currently believe any material losses from these claims are both probable and reasonably estimated, and therefore, has not recognized any material loss contingency amounts for this complaint as of March 31, 2015. Due to the early stages of the claim and the lack of specific damages identified, Alliant Energy is currently unable to provide an estimate of potential loss or range of potential loss. (d) Guarantees and Indemnifications - RMT - In 2013, Alliant Energy sold RMT. RMT provided renewable energy services, including construction and high voltage connection services for wind and solar projects. As part of the sale, Alliant Energy indemnified the buyer for any claims, including claims of warranty under the project obligations that were commenced or are based on actions that occurred prior to the sale, except for liabilities already accounted for through adjustments to the purchase price. The indemnification obligations either cease to exist when the statute of limitation for such claims is met or, in the case of RMT’s projects, when the warranty period under the agreements expires. The warranty periods for RMT’s projects generally range from 12 to 60 months with the latest expiring in 2016. Alliant Energy also continues to guarantee RMT’s performance obligations related to certain of RMT’s projects that were commenced prior to Alliant Energy’s sale of RMT. As of March 31, 2015, Alliant Energy had $251 million of performance guarantees outstanding, with $128 million, $48 million and $75 million currently expected to expire in 2015, 2016 and 2017, respectively. The expiration of these performance guarantees may be extended depending on when all valid warranty claims are resolved for the respective projects. Although Alliant Energy has received warranty claims related to certain of these projects, it does not currently believe that material losses are both probable and reasonably estimated, and therefore, has not recognized any material liabilities related to these matters as of March 31, 2015. Due to the early stages of the warranty claims, Alliant Energy is currently unable to provide an estimate of potential loss or range of potential loss. Whiting Petroleum - In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Whiting Petroleum is an independent oil and gas company. Alliant Energy continues to guarantee the obligations related to the abandonment of certain platforms off the coast of California and related onshore plant and equipment that were owned by Whiting Petroleum prior to Alliant Energy’s sale of Whiting Petroleum. The guarantee does not include a maximum limit. As of March 31, 2015, the present value of the abandonment obligations is estimated at $35 million. Alliant Energy believes that no payments will be made under this guarantee. Alliant Energy has not recognized any material liabilities related to this guarantee as of March 31, 2015. (e) Environmental Matters - MGP Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. IPL and WPL are currently monitoring and/or remediating 25 and 5 sites, respectively. Included in IPL’s sites is a Minnesota site for which responsibility of monitoring and/or remediating the site was transferred to the buyer as part of the sale of IPL’s Minnesota natural gas distribution assets. Environmental liabilities related to these MGP sites are recorded based upon periodic studies. Such amounts are based on the best current estimate of the remaining amount to be incurred for investigation, remediation and monitoring costs for those sites where the investigation process has been or is substantially completed, and the minimum of the estimated cost range for those sites where the investigation is in its earlier stages. There are inherent uncertainties associated with the estimated remaining costs for MGP projects primarily due to unknown site conditions and potential changes in regulatory agency requirements. It is possible that future cost estimates will be greater than current estimates as the investigation process proceeds and as additional facts become known. The amounts recognized as liabilities are reduced for expenditures incurred and are adjusted as further information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted. At March 31, 2015, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Range of estimated future costs |  | $14 |  | - | $34 |  |  | $13 |  | - | $31 |  |  | $1 |  | - | $3
Current and non-current environmental liabilities | 16 |  | 14 |  | 2
WPL Consent Decree - In 2009, the EPA sent a notice of violation to WPL as an owner and the operator of Edgewater, Nelson Dewey and Columbia alleging that the owners of such EGUs failed to comply with appropriate pre-construction review and permitting requirements and as a result violated the PSD program requirements, Title V Operating Permit requirements of the CAA and the Wisconsin State Implementation Plan. In 2010, the Sierra Club filed complaints against WPL, as owner and operator of Nelson Dewey and Columbia, and separately as owner and operator of Edgewater, based on allegations that modifications were made at the facilities without complying with the PSD program requirements, Title V Operating Permit requirements of the CAA and state regulatory counterparts contained within the Wisconsin State Implementation Plan designed to implement the CAA. In April 2013, WPL, along with the other owners of Edgewater and Columbia, entered into a Consent Decree with the EPA and the Sierra Club to resolve the claims relating to Edgewater, Columbia and Nelson Dewey, while admitting no liability. In June 2013, the Consent Decree was approved by the U.S. District Court for the Western District of Wisconsin, thereby resolving all claims against WPL. Under the Consent Decree, WPL is required to install the following emission controls systems:
• | Selective catalytic reduction system at Edgewater Unit 5 by May 1, 2013 (placed in service in 2012);
• | Scrubbers and baghouses at Columbia Units 1 and 2 by December 31, 2014 (placed in service in 2014);
• | Scrubber and baghouse at Edgewater Unit 5 by December 31, 2016; and
• | Selective catalytic reduction system at Columbia Unit 2 by December 31, 2018.
WPL is also required to fuel switch or retire Nelson Dewey Units 1 and 2 and Edgewater Unit 3 by December 31, 2015, and Edgewater Unit 4 by December 31, 2018. In addition, the Consent Decree establishes emission rate limits for SO2, NOx and particulate matter for Columbia Units 1 and 2, Nelson Dewey Units 1 and 2 and Edgewater Units 4 and 5. The Consent Decree also includes annual plant-wide emission caps for SO2 and NOx for Columbia, Edgewater and Nelson Dewey. In addition, WPL will complete approximately $7 million in environmental mitigation projects. Final recovery of the costs expected to be incurred related to the Consent Decree will be decided by the PSCW in future rate cases or other proceedings. Alliant Energy and WPL currently expect to recover any material costs incurred by WPL related to compliance with the terms of the Consent Decree from WPL’s electric customers, except for costs related to certain of the environmental mitigation projects. Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however future capital investments and/or modifications to EGUs to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Clean Air Visibility Rule, MATS Rule, Industrial Boiler and Process Heater Maximum Achievable Control Technology Rule, Ozone National Ambient Air Quality Standards Rule, SO2 National Ambient Air Quality Standards Rule, Federal Clean Water Act including Section 316(b), Effluent Limitation Guidelines, Hydroelectric Fish Passage Device, CCR Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including carbon emissions from new (CAA Section 111(b)) and existing (CAA Section 111(d)) fossil-fueled EGUs. Some recent developments concerning these environmental matters are included below: Air Quality - MATS Rule - In March 2015, the EPA approved an extension to the MATS Rule compliance deadline from April 2015 to April 2016 for IPL’s M.L. Kapp Unit 2. Land and Solid Waste - CCR Rule - Refer to Note 10 for discussion of the final CCR Rule, including additional AROs that are expected to be recognized in the second quarter of 2015.
WPL [Member] |
Commitments and Contingencies Disclosure | COMMITMENTS AND CONTINGENCIES (a) Capital Purchase Obligations - Various contractual obligations contain minimum future commitments related to capital expenditures for certain construction projects. IPL’s projects include the installation of a scrubber at Lansing Unit 4 to reduce SO2 emissions. WPL’s projects include the installation of a scrubber and baghouse at Edgewater Unit 5 to reduce SO2 and mercury emissions, and generation maintenance and performance improvements at Columbia Units 1 and 2. At March 31, 2015, Alliant Energy’s, IPL’s and WPL’s minimum future commitments related to certain contractual obligations for these projects were $26 million, $2 million and $24 million, respectively. (b) Operating Expense Purchase Obligations - Various commodity supply, transportation and storage contracts help meet obligations to provide electricity and natural gas to utility customers. Other operating expense purchase obligations with various vendors provide other goods and services. At March 31, 2015, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Purchased power (a): |  |  |  |  |
DAEC (IPL) |  | $1,510 |  |  |  | $1,510 |  |  |  | $— |
Other | 220 |  |  | 1 |  |  | 219 |
| 1,730 |  |  | 1,511 |  |  | 219 |
Natural gas | 228 |  |  | 120 |  |  | 108 |
Coal (b) | 264 |  |  | 113 |  |  | 151 |
SO2 emission allowances | 22 |  |  | 22 |  |  | — |
Other (c) | 39 |  |  | 29 |  |  | 10 |
|  | $2,283 |  |  |  | $1,795 |  |  |  | $488 |
(a) | Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased.
(b) | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of March 31, 2015 regarding expected future usage, which is subject to change.
(c) | Includes individual commitments incurred during the normal course of business that exceeded $1 million at March 31, 2015.
(c) Legal Proceedings - Flood Damage Claims - In June 2013, several plaintiffs purporting to represent a class of residential and commercial property owners filed a complaint against CRANDIC, Alliant Energy and various other defendants in the Iowa District Court for Linn County. Plaintiffs assert claims of negligence and strict liability based on their allegations that CRANDIC (along with other defendants) caused or exacerbated flooding of the Cedar River in June 2008. In July 2013, the case was removed from state court to federal court based on federal jurisdiction. In September 2013, the U.S. District Court for the Northern District of Iowa dismissed the Plaintiffs’ claims and transferred the case for resolution to the Surface Transportation Board, the administrative agency that oversees the Interstate Commerce Commission Termination Act. In October 2013, the Plaintiffs appealed the federal court’s dismissal of the case to the Eighth Circuit Court of Appeals. Alliant Energy and CRANDIC believe the case is without merit and will continue to vigorously contest the case. As a result, Alliant Energy does not currently believe any material losses from these claims are both probable and reasonably estimated, and therefore, has not recognized any material loss contingency amounts for this complaint as of March 31, 2015. Due to the early stages of the claim and the lack of specific damages identified, Alliant Energy is currently unable to provide an estimate of potential loss or range of potential loss. (d) Guarantees and Indemnifications - RMT - In 2013, Alliant Energy sold RMT. RMT provided renewable energy services, including construction and high voltage connection services for wind and solar projects. As part of the sale, Alliant Energy indemnified the buyer for any claims, including claims of warranty under the project obligations that were commenced or are based on actions that occurred prior to the sale, except for liabilities already accounted for through adjustments to the purchase price. The indemnification obligations either cease to exist when the statute of limitation for such claims is met or, in the case of RMT’s projects, when the warranty period under the agreements expires. The warranty periods for RMT’s projects generally range from 12 to 60 months with the latest expiring in 2016. Alliant Energy also continues to guarantee RMT’s performance obligations related to certain of RMT’s projects that were commenced prior to Alliant Energy’s sale of RMT. As of March 31, 2015, Alliant Energy had $251 million of performance guarantees outstanding, with $128 million, $48 million and $75 million currently expected to expire in 2015, 2016 and 2017, respectively. The expiration of these performance guarantees may be extended depending on when all valid warranty claims are resolved for the respective projects. Although Alliant Energy has received warranty claims related to certain of these projects, it does not currently believe that material losses are both probable and reasonably estimated, and therefore, has not recognized any material liabilities related to these matters as of March 31, 2015. Due to the early stages of the warranty claims, Alliant Energy is currently unable to provide an estimate of potential loss or range of potential loss. Whiting Petroleum - In 2004, Alliant Energy sold its remaining interest in Whiting Petroleum. Whiting Petroleum is an independent oil and gas company. Alliant Energy continues to guarantee the obligations related to the abandonment of certain platforms off the coast of California and related onshore plant and equipment that were owned by Whiting Petroleum prior to Alliant Energy’s sale of Whiting Petroleum. The guarantee does not include a maximum limit. As of March 31, 2015, the present value of the abandonment obligations is estimated at $35 million. Alliant Energy believes that no payments will be made under this guarantee. Alliant Energy has not recognized any material liabilities related to this guarantee as of March 31, 2015. (e) Environmental Matters - MGP Sites - IPL and WPL have current or previous ownership interests in various sites that are previously associated with the production of gas for which IPL and WPL have, or may have in the future, liability for investigation, remediation and monitoring costs. IPL and WPL are working pursuant to the requirements of various federal and state agencies to investigate, mitigate, prevent and remediate, where necessary, the environmental impacts to property, including natural resources, at and around these former MGP sites in order to protect public health and the environment. IPL and WPL are currently monitoring and/or remediating 25 and 5 sites, respectively. Included in IPL’s sites is a Minnesota site for which responsibility of monitoring and/or remediating the site was transferred to the buyer as part of the sale of IPL’s Minnesota natural gas distribution assets. Environmental liabilities related to these MGP sites are recorded based upon periodic studies. Such amounts are based on the best current estimate of the remaining amount to be incurred for investigation, remediation and monitoring costs for those sites where the investigation process has been or is substantially completed, and the minimum of the estimated cost range for those sites where the investigation is in its earlier stages. There are inherent uncertainties associated with the estimated remaining costs for MGP projects primarily due to unknown site conditions and potential changes in regulatory agency requirements. It is possible that future cost estimates will be greater than current estimates as the investigation process proceeds and as additional facts become known. The amounts recognized as liabilities are reduced for expenditures incurred and are adjusted as further information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted. At March 31, 2015, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Range of estimated future costs |  | $14 |  | - | $34 |  |  | $13 |  | - | $31 |  |  | $1 |  | - | $3
Current and non-current environmental liabilities | 16 |  | 14 |  | 2
WPL Consent Decree - In 2009, the EPA sent a notice of violation to WPL as an owner and the operator of Edgewater, Nelson Dewey and Columbia alleging that the owners of such EGUs failed to comply with appropriate pre-construction review and permitting requirements and as a result violated the PSD program requirements, Title V Operating Permit requirements of the CAA and the Wisconsin State Implementation Plan. In 2010, the Sierra Club filed complaints against WPL, as owner and operator of Nelson Dewey and Columbia, and separately as owner and operator of Edgewater, based on allegations that modifications were made at the facilities without complying with the PSD program requirements, Title V Operating Permit requirements of the CAA and state regulatory counterparts contained within the Wisconsin State Implementation Plan designed to implement the CAA. In April 2013, WPL, along with the other owners of Edgewater and Columbia, entered into a Consent Decree with the EPA and the Sierra Club to resolve the claims relating to Edgewater, Columbia and Nelson Dewey, while admitting no liability. In June 2013, the Consent Decree was approved by the U.S. District Court for the Western District of Wisconsin, thereby resolving all claims against WPL. Under the Consent Decree, WPL is required to install the following emission controls systems:
• | Selective catalytic reduction system at Edgewater Unit 5 by May 1, 2013 (placed in service in 2012);
• | Scrubbers and baghouses at Columbia Units 1 and 2 by December 31, 2014 (placed in service in 2014);
• | Scrubber and baghouse at Edgewater Unit 5 by December 31, 2016; and
• | Selective catalytic reduction system at Columbia Unit 2 by December 31, 2018.
WPL is also required to fuel switch or retire Nelson Dewey Units 1 and 2 and Edgewater Unit 3 by December 31, 2015, and Edgewater Unit 4 by December 31, 2018. In addition, the Consent Decree establishes emission rate limits for SO2, NOx and particulate matter for Columbia Units 1 and 2, Nelson Dewey Units 1 and 2 and Edgewater Units 4 and 5. The Consent Decree also includes annual plant-wide emission caps for SO2 and NOx for Columbia, Edgewater and Nelson Dewey. In addition, WPL will complete approximately $7 million in environmental mitigation projects. Final recovery of the costs expected to be incurred related to the Consent Decree will be decided by the PSCW in future rate cases or other proceedings. Alliant Energy and WPL currently expect to recover any material costs incurred by WPL related to compliance with the terms of the Consent Decree from WPL’s electric customers, except for costs related to certain of the environmental mitigation projects. Other Environmental Contingencies - In addition to the environmental liabilities discussed above, various environmental rules are monitored that may have a significant impact on future operations. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Given uncertainties regarding the outcome, timing and compliance plans for these environmental matters, the complete financial impact of each of these rules is not able to be determined; however future capital investments and/or modifications to EGUs to comply with certain of these rules could be significant. Specific current, proposed or potential environmental matters include, among others: Cross-State Air Pollution Rule, Clean Air Visibility Rule, MATS Rule, Industrial Boiler and Process Heater Maximum Achievable Control Technology Rule, Ozone National Ambient Air Quality Standards Rule, SO2 National Ambient Air Quality Standards Rule, Federal Clean Water Act including Section 316(b), Effluent Limitation Guidelines, Hydroelectric Fish Passage Device, CCR Rule, and various legislation and EPA regulations to monitor and regulate the emission of greenhouse gases, including carbon emissions from new (CAA Section 111(b)) and existing (CAA Section 111(d)) fossil-fueled EGUs. Some recent developments concerning these environmental matters are included below: Air Quality - MATS Rule - In March 2015, the EPA approved an extension to the MATS Rule compliance deadline from April 2015 to April 2016 for IPL’s M.L. Kapp Unit 2. Land and Solid Waste - CCR Rule - Refer to Note 10 for discussion of the final CCR Rule, including additional AROs that are expected to be recognized in the second quarter of 2015.

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