AltaGas : March Investor Presentation

Forward-Looking Information

Forward Looking Information

This presentation contains forward-looking information (forward-looking statements). Words such as "guidance", "may", "can", "would", "could", "should", "will", "intend", "plan", "anticipate", "believe", "aim", "seek", "propose", "contemplate", "estimate", "focus", "strive", "forecast", "expect", "project", "target", "potential", "objective", "continue", "outlook", "vision", "opportunity" and similar expressions suggesting future events or future performance, as they relate to the Company or any affiliate of the Company, are intended to identify forward-looking statements. In particular, this presentation contains forward-looking statements with respect to, among other things, business objectives, expected growth, results of operations, performance, business projects and opportunities and financial results. Specifically, such forward-looking statements included in this document include, but are not limited to, statements with respect to the following2021 Normalized EPS guidance of $1.45 - $1.55 per share; 2021 Normalized EBITDA guidance of $1.4 billion - $1.5 billion; self-funded $910 million 2021 capital program; anticipated contract type and counterparty credit quality in 2021; anticipated allocation of Utilities segment revenue between retail and commercial customers in 2021; allocation of anticipated 2021 normalized EBITDA by segment and underlying drivers; 2021+ long-term vision and strategy; a targeted 130-150 bps improvement in WGL's ROE over 2021; expected Utilities rate base growth through 2025; status and expected timing for decisions in pending rate case settlements; expected allocation of utilities capital in 2021; anticipated export capacity; expected growth drivers for the Utilities and Midstream segments; estimated annual synergies of approximately $30 million within the combined platform with Petrogas; anticipated global demand for propane and butane through 2030; Midstream and Utilities strategies; and advancement of AltaGas' global export strategy. Such statements reflect AltaGas' current expectations, estimates, and projections based on certain material factors and assumptions at the time the statement was made. Material assumptions include: dividend levels; processing and fractionation volumes; number of ships and export levels from the Ferndale facility, current forward curves, effective tax rates, the U.S./Canadian dollar exchange rate, the impact of the COVID-19 pandemic, financing initiatives, propane price differentials, degree day variance from normal, pension discount rate, the performance of the businesses underlying each sector, impacts of the hedging program, commodity prices, weather, frac spread, access to capital, timing and receipt of regulatory approvals, including pending rate cases, planned and unplanned plant outages, timing of in-service dates of new projects and acquisition and divestiture activities, operational expenses, returns on investments, and dividend levels.

AltaGas' forward-looking statements are subject to certain risks and uncertainties which could cause results or events to differ from current expectations, including, without limitation: risk related to COVID -19; health and safety risks; risks related to the integration of Petrogas; operating risks; regulatory risks; cyber security, information, and control systems; litigation risk; climate-related risks, including carbon pricing; changes in law; political uncertainty and civil unrest; infrastructure risks; service interruptions; decommissioning, abandonment and reclamation costs; reputation risk; weather data; Indigenous land and rights claims; crown duty to consult with Indigenous peoples; capital market and liquidity risks; general economic conditions; internal credit risk; foreign exchange risk; debt financing, refinancing, and debt service risk; interest rates; technical systems and processes incidents; dependence on certain partners; growth strategy risk; construction and development; transportation of petroleum products; impact of competition in AltaGas' businesses; counterparty credit risk; market risk; composition risk; collateral; rep agreements; delays in U.S. Federal Government budget appropriations; market value of common shares and other securities; variability of dividends; potential sales of additional shares; volume throughput; natural gas supply risk; risk management costs and limitations; underinsured and uninsured losses; commitments associated with regulatory approvals for the acquisition of WGL; securities class action suits and derivative suits; electricity and resource adequacy prices; cost of providing retirement plan benefits; labor relations; key personnel; failure of service providers; compliance with Section 404(a) of Sarbanes-Oxley Act; and the other factors discussed under the heading "Risk Factors" in the Corporation's Annual Information Form for the year ended December 31, 2020 and set out in AltaGas' other continuous disclosure documents. Many factors could cause AltaGas' or any particular business segment's actual results, performance or achievements to vary from those described in this press release, including, without limitation, those listed above and the assumptions upon which they are based proving incorrect. These factors should not be construed as exhaustive. Should one or more of these risks or uncertainties materialize, or should assumptions underlying forward-looking statements prove incorrect, actual results may vary materially from those described in this presentation as intended, planned, anticipated, believed, sought, proposed, estimated, forecasted, expected, projected or targeted and such forward-looking statements included in this presentation, should not be unduly relied upon. The impact of any one assumption, risk, uncertainty, or other factor on a particular forward-looking statement cannot be determined with certainty because they are interdependent and AltaGas' future decisions and actions will depend on management's assessment of all information at the relevant time. Such statements speak only as of the date of this presentation. AltaGas does not intend, and does not assume any obligation, to update these forward-looking statements except as required by law. The forward-looking statements contained in this presentation are expressly qualified by these cautionary statements.

Financial outlook information contained in this presentation about prospective financial performance, financial position, or cash flows is based on assumptions about future events, including economic conditions and proposed courses of action, based on AltaGas management's (Management) assessment of the relevant information currently available. Readers are cautioned that such financial outlook information contained in this presentation should not be used for purposes other than for which it is disclosed herein.

Additional information relating to AltaGas, including its quarterly and annual MD&A and Consolidated Financial Statements, AIF, and press releases are available through AltaGas' website atwww.altagas.caor through SEDAR at www.sedar.com.

Non-GAAP Measures

This presentation contains references to certain financial measures that do not have a standardized meaning prescribed by US GAAP and may not be comparable to similar measures presented by other entities. The non-GAAP measures and their reconciliation to US GAAP financial measures are shown in AltaGas' Management's Discussion and Analysis (MD&A) as at and for the period ended December 31, 2020. These non-GAAP measures provide additional information that management believes is meaningful regarding AltaGas' operational performance, liquidity and capacity to fund dividends, capital expenditures, and other investing activities. Readers are cautioned that these non-GAAP measures should not be construed as alternatives to other measures of financial performance calculated in accordance with US GAAP.

EBITDA is a measure of AltaGas' operating profitability prior to how business activities are financed, assets are amortized, or earnings are taxed. EBITDA is calculated from the Consolidated Statements of Income using net income (loss) after taxes adjusted for pre tax depreciation and amortization, interest expense, and income taxes. Normalized EBITDA includes additional adjustments for transaction costs (recoveries) related to acquisitions and dispositions, merger commitment costs (recoveries) due to a change in timing related to certain WGL merger commitments, unrealized losses (gains) on risk management contracts, non-controlling interest of certain investments to which HLBV accounting is applied, losses on investments, gains on sale of assets, restructuring costs, dilution loss and other adjustments to equity income related to the acquisition of Petrogas, gain on re-measurement of previously held equity investment in AIJVLP,

COVID-19 related costs, provisions on assets, provisions on investments accounted for by the equity method, distributed generation asset related investment tax credits, foreign exchange losses (gains), and accretion expenses related to asset retirement obligations. In addition to the dilution loss, the other adjustments to equity income primarily included amounts related to severance, transaction costs, and impairment losses related to the acquisition of Petrogas. COVID-19 related costs normalized in 2020 were primarily comprised of credit losses that were incremental and directly attributable to the COVID-19 pandemic and charges incurred to support remote work arrangements. AltaGas presents normalized EBITDA as a supplemental measure. Normalized EBITDA is used by Management to enhance the understanding of AltaGas' earnings over periods. The metric is frequently used by analysts and investors in the evaluation of entities within the industry as it excludes items that can vary substantially between entities depending on the accounting policies chosen, the book value of assets, and the capital structure.

Normalized earnings per share or normalized EPS is calculated with reference to normalized net income. Normalized net income represents net income (loss) applicable to common shares adjusted for the after-tax impact of transaction costs (recoveries) related to acquisitions and dispositions, merger commitment costs (recoveries) due to a change in timing related to certain WGL merger commitments, unrealized losses (gains) on risk management contracts, losses on investments, gains on sale of assets, provisions on assets, provisions on investments accounted for by the equity method, restructuring costs, dilution loss and other adjustments to equity income related to the acquisition of Petrogas, gain on re-measurement of previously held equity investment in AIJVLP, COVID-19 related costs, gain on redemption of preferred shares, unitary tax adjustment related to the acquisition of WGL and U.S. asset sales, and statutory tax rate change. Normalized net income is used by Management to enhance the comparability of AltaGas' earnings, as it reflects the underlying performance of AltaGas' business activities.

Who We Are

Our Vision

A Leading North American infrastructure company that connects NGLs and natural gas to domestic and global markets.

Our Mission

To improve quality of life by safely and reliably connecting customers to affordable sources of energy for today and tomorrow.

Our Values

Every day our team of approximately 3,000 people strong is guided by our core values. These values are not negotiable. They are our fuel, foundation and focus.

Our Foundational Principles:

Work Safely,

Think ResponsiblyAct With Integrity

Make Informed Decisions

Achieve ResultsInvest in our People & Foster

Access to reliable and affordable energy is fundamental in the pursuit of improved quality of life, reduced physical strains, improved access to education, and to fuel economic expansion. At AltaGas, we take our responsibility in delivering energy seriously. At our core, we are committed to maintaining safe and reliable operations, delivering the critical energy our customers need, and honoring the social and moral contract that we have with the communities we serve.

Diversity

Understanding Our Business

What We Do: Operate a diversified, low-risk, high-growth Utilities and Midstream business that is focused on delivering resilient and durable value for our stakeholders.

Integrated Midstream Business - from wellhead to global markets

maertsdiM

~4,700 rail cars, >6 MMBls Storage, >125 trucks, >250 trailers: FSK rail/truck; Sarnia, Strathcona & Griffith storage; Townsend truck & rail; NGL pipelines, treating & storage

NGL Extraction & Fractionation

64,000 Bbl/d2

6 Facilities: North Pine, Harmattan, EEEP, JEEP, PEEP, Younger

Sales: Local and U.S. Markets

Transportation, Storage &

C3 & C4

Fort Saskatchewan - Local Blending

Export

Contract Type5

Global Markets

VLGC to Asia

§ Take-or-Pay &

Cost-of-Service § Fee-for-Service

& Global Markets § Merchant - Hedged § Merchant -

Unhedged

seitilitU

• • Leverage utility storage and transportation resources to a derive a profit through physical and financial contracts (shared).

Retail Energy Marketing

Sell natural gas and power directly to residential, commercial, and industrial customers

Contract Type5

§ A- and Above § BBB+ to BBB- § BB+ to BB- § B+ and Below

42%

Midstream

57%

Utilities

1% Corporate/Other

Other Services

Efficiency, Technology, Transportation and Generation

2021e Utility Revenues

§ Residential § Commercial & Industrial

Notes: 1. Based on ALA working interest capacity in FG&P and extraction 2. Based on ALA 100% working interest facilities and ALA % capacity in non-operated facilities 3. Includes RIPET and Ferndale 4. As at February 25, 2021. 5. Based on 2021 guidance 6. Reflects dividend increase announced on December 10, 2020. See "Forward-looking Information.

1.7 million customers in stable and growing jurisdictions

~70% of Utilities revenue protected § Fixed distribution charges

§

Decoupled rate structures in Maryland and Virginia

Expect limited sensitivity on unprotected revenue

• § Currently in lower demand spring and summer

• § ~70% of revenue derived from residential customers

• § Uncollected revenue applied for in future rates

Rate Regulated Utilities Provide Stability and Growth

~57% of 2021e normalized EBITDA1 from Utilities Segment

Premier Midstream Business

Leveraging Core Export Strategy Structural Advantage to Markets in Asia

Leverage core export strategy and access to premium global pricing to attract volumes

~70% from investment grade customers

~65% from take-or-pay contracts and fee-for-service ~70% of 2021 RIPET volumes hedged (includes tolling); plan continued active hedging in 2021

2021e Normalized EBITDA1

Credit Quality

§ A- and Above § BBB+ to BBB- § BB+ to BB- § B+ and Below

Contract Type

§ Take-or-Pay &

Cost-of-Service § Fee-for-Service § Merchant -

Expected to

be Hedged § Merchant -

Less likely to

be Hedged

Corporate Counterparty Credit

Corporate Contract Mix

~79% of 2021e normalized EBITDA1 from rate regulated utilities and take or pay contracts

Top 5 producers

2020e

Contract Type

UtilitiesTake or PayFee for serviceMerchant - Likely to be

Hedged

Merchant - Less likely to be Hedged

~86% of 2021e normalized EBITDA1 underpinned by low-risk regulated and contracted assets (take-or-pay and fee-for-service)

Merchant normalized EBITDA largely underpinned by energy export strategy and demand pull from Asia

~35% of RIPET's 2021e volumes are under long-term take or pay arrangements with an average remaining term of ~7 years

2020 Key Accomplishments

Strong execution and focus positions AltaGas for durable long-term value creation

Operational Priorities

Financial Priorities

Utilities

Closed the ROE gap at WGL by 150 bps, meeting our target

Successfully reduced leaks by >15% Y/Y and greatly improved the customer experience

Generated more timely recovery of expenses and returns on capital deployed through operational discipline

Delivered critical, clean and affordable natural gas in a safe and reliable manner, amidst the COVID-19 pandemic

Midstream

Completed Townsend 2B (200 MMcf/d) and North Pine (10,000 Bbl/d) expansions

Continued to ramp up and de-risk volumes at the RIPET exportfacility achieving the 50,000 Bbl/d exit target, despite COVID-19 headwinds

Significantly advanced global energy export strategy through increased operational ownership in Petrogas

Materially de-risked counterparty credit exposure and alignment with industry-leading operators in NEBC

Achieved upper-end of previously stated 2020 Normalized EBITDA1 guidance range ($1.275 - $1.325 billion) and exceeded previously stated 2020 Normalized EPS guidance range ($1.20 - $1.30)

Deployed ~$900 million self-funded capital program Executed ~$440 million of non-core asset sales Refinanced 2020 debt maturities at lower interest rates

Continue to de-lever the capital structure, maintain investment grade credit rating, and stagger, extend and de-risk AltaGas' maturity profile

Improved 2020 financial indicators

Notes: 1. Non-GAAP financial measure; see discussion in the advisories; 2. Represents growth in the core businesses net of the impact of $117 million in lost EBITDA in 2020 associated with 2019 asset sales. See "Forward-looking Information"

2021 Financial Guidance Highlights ($CAD unless otherwise noted)

4%

$1.45 - 1.55 $1.45-1.55

$1.4 -1.5B

~$910M

Annual Dividend Increase

Anticipated Normalized Anticipated Normalized

EPS1

Anticipated Normalized

Planned Capital Program

EPS1

EBITDA1

We're building a diversified, low-risk, high-growth energy infrastructure business that is focused on delivering resilient and durable value for our stakeholders. Our goal is compounding returns over time.

1. Non-GAAP measure; see discussion in the advisories

See "Forward-looking Information"

Our corporate priorities are on delivering, de-levering, de-risking, investing and executing across all business segments.

Utilities Strategy - Drive Operational Excellence

Priorities

Maintain safe and reliable infrastructure

Enhance overall returns via complementary businesses and cost-reduction initiatives

Attract and retain customers through exceptional customer service

Improve asset management capabilities

Enhance the value proposition for our customers

WGL ROE Strategy

Path to earning our allowed returns at WGL

Strategy in place with a clear line of sight to reach allowed returns during 2021

Key initiatives to achieving allowed returns:

• 1. Capital Discipline:

  §

  Accelerated Replacement Programs ensure timely recovery of invested capital

  § Drive returns through the execution of strategic projects

• 2. Rate Cases: update rates to reflect current plant and operating costs

  • § DC rate case filed on January 13, 2020; Settlement Agreement approved Feb 24, 2021; New rates to be effective April 1, 2021. 1

  • § MD rate case filed on August 28, 2020; decision expected around end of Q1 2021

• 3. Cost Management:

  • § Optimization and cost-reduction initiatives underway

  • § Leak remediation program launched with expected cost-savings realized through to year-end 2021

Anticipated Return On Equity & Expected Timeline

~9.4%

150 bps

Current

ROE

DC/MD Rate Case OrderCost Reduction

Initiatives

2021e

See "Forward-looking Information"

Utilities Segment Capital Spend

Disciplined approach to capital focused on strategic projects and Accelerated Replacement Programs

ARP programs are designed for improved safety and reliability, better customer outcomes and environmental benefits. They also provide immediate returns and increase capital efficiency.

2020e Utilities Capital1

2021e Utilities Capital

~US$510 million

~US$565 million

Increased utilization of ARPs

1) 2020e Utilities Capital updated for most recent internal forecast See "Forward-looking Information"

Summary of Recent Rate Case Filings

Focused on timely recovery of capital

Most Recent Rate Case Filed	Revenue	ROE	Equity Thickness
SEMCO (Michigan)	Filed May 31, 2019	Received: US$19.9MM	Received: 9.87%	Received: 54%1
WGL (Maryland)	Filed August 28, 2020	Requested: US$28.4MM	Requested: 10.45%	Requested: 54.55%
CINGSA (Alaska)	Filed in 2018	Received: US($9)MM	Received: 10.25%	Received: 53%
WGL (Virginia)	Filed July 31, 2018	Received: US$13.2MM	Received: 9.2%	Received: 53.5%
WGL (DC)	Filed January 13, 2020	Received: US$19.5MM	Received: 9.25%	Received: 52.1%

1. Represents SEMCO's permanent equity capital, excludes effect of deferred income tax.

Supportive Regulatory Environment for Utilities

Utility

SEMCO Michigan

2020 YE Rate Base

($US)

$719MM

Customers

~313,000

Allowed ROE and Equity Thickness

• § Distribution rates approved under cost of service model.

• § Projected test year used for rate cases with 10 month limit to issue a rate order.

  9.87% 54%1

• § Rate case filed in May 2019 settled in November and approved in December. New rates effective January 1, 2020.

• § Settlement terms include a rate increase of US$19.9 million, a renewed Main Replacement Program (MRP) from 2021-2025, and a new Infrastructure Reliability Improvement Program (IRIP) 2020-2025.

§ Distribution rates approved under cost of service model using historicalENSTAR Alaska

$256MM

~149,000

• 11.875% test year and allows for known and measurable changes.

• 51.81% §

Rate Order approving rate increase issued on September 22, 2017.

Final rates effective November 1, 2017.

ENSTAR, 3

CINGSA Alaska

$66MM2

electric utilities 10.25%

and 5 other 53.00% customers

• § Distribution rates approved under cost of service model using historical test year and allows for known and measurable changes.

• § Rate case filed in 2018 based on 2017 historical test year.

• § Rate case decision issued in August 2019.

• § Required to file next rate case by July 1, 2021 based on 2020 test year.

• 1. Reflects SEMCO permanent capital excluding effect of deferred income tax.

• 2. Reflects 65% ownership

  See "Forward-looking Information"

Regulatory Update

Supportive Regulatory Environment for Utilities

Utility

2020 YE Rate Base

($US)

Customers

§ Distribution rates approved under cost of service model.

Allowed ROE and Equity ThicknessRegulatory Update

~540,000

9.20% 53.5%

§

Rate case filed on July 31, 2018. On December 20, 2019 the Commission granted US$13.2 million rate increase which reflected the transfer of revenues associated with the US$102 million of SAVE investment from the SAVE rate rider to base rates; (ii) an ROE of 9.2%; (iii) the amortization of unprotected excess deferred income tax over eight years; and (iv) the refund of US$25.5 million TCJA liability over a 12-month period as a sur-credit.

• § Distribution rates approved under cost of service model.

• § Filed rate case on January 13, 2020 to increase base rates

  ~165,000

  • § Distribution rates approved under cost of service model.

    ~500,000

    9.70% 53.5%

  • § Rate case filed on August 28, 2020 to increase base rates by $28.4 million, including $5.8 million currently collected through its strategic infrastructure development and enhancement, or STRIDE, rider. This results in a $22.6 million, or 3.95%, net overall non-gas revenue increase being proposed.

  • § The proposed rate requested a 10.45% ROE with 54.55% equity thickness based on a rate base valued at $1.225 billion for a test year ended March 31, 2020.

  • § Rebuttal testimony filed December 8. Evidentiary hearing held January 7 to 11, 2021.

  • § New rates from this application is expected to take effect around late March 2021.

  9.25% 52.1%

• § Settlement agreement filed December 8, 2020 includes an increase in base rates by US$19.5 million, including approximately US$9 million pertaining to a PROJECTpipes surcharge that customers are currently paying in the form of a rate rider.

• § The settlement agreement also includes a 9.25% ROE with a 52.1% equity thickness

• § Settlement Agreement approved Feb 24, 2021. New rates to be effective April 1, 2021.

See "Forward-looking Information"

Notes: 1) Settlement Agreement filed December 8, 2020; awaiting Commission approval.

Accelerated Replacement Program

Utility

Location

Program

Michigan

§ 2019 rate case settlement provides for a renewed Mains Replacement Program for 2021-2025 with totalspending ~ $60 million and the introduction of a new Infrastructure Replacement Improvement Program for 2020-2025 with total spending ~$55 million beginning in 2021.

Virginia

• § Authorized to invest US$500M, including cost of removal over a five-year calendar period ending in 2022.

• § Expect to incur approximately US$130 million SAVE capital expenditure in 2021.

Maryland

§ STRIDE renewal approved in 2018 to be US$350M over 5 years (2019-2023).

Washington

D.C.

§ On December 11, 2020, the Commission approved a US$150 million, three-year PROJECTpipes 2 plan from 2021-2023.

> US$1B of Approved ARP Capital Projects in Place

See "Forward-looking Information"

Our Midstream Strategy is Straightforward

Maximize utilization of existing assets and pursue capital efficient high-return expansions

• § Continue to build upon our export competency

• § Diversify and grow our customer base to help mitigate counterparty risk

• § Optimize existing rail infrastructure to gain scale and efficiencies

• § Increase throughput at existing facilities while maintaining top-tier operating costs and environmental standards

• § Leverage and maintain strong relationships with First Nations, regulators and all partners

• § Mitigate commodity risk through effective hedging programs and risk management systems

InvestGrowLeveragePartnerProtect

Leverage export strategy and our integrated value chain to attract volumes

See "Forward-looking Information"

Midstream: Who We Are

Integrated Midstream Business - from wellhead to global markets

We're a high-quality operator that has built our business with purpose and is well-positioned for where we believe the market is headed over the next three-to-five years.

50-80k Bbl/sd Capacity Propane

>50k Bbls/d Capacity Propane & Butane

Gas Gathering & Processing

2.25Bcf/d1 Processing

PEEP & Younger

12 Facilities: Townsend, Aitken Creek, Nig Creek, Harmattan, Gordondale, Blair Creek, EEEP, JEEP,

Transportation, Storage & Rail Logistics

~4,700 rail cars, >6 MMBbls Storage, >125 trucks, >250 trailers

FSK rail and truck terminal, Sarnia and Strathcona terminals, Griffith storage facilities, and Townsend truck terminal, rail

terminal, NGL pipelines; treating, storage

Export

>130,000 Bbls/d3 Export capability 2 Terminals: RIPET,

Ferndale

Notes: 1. Based on ALA working interest capacity in FG&P and extraction 2. Based on ALA 100% working interest facilities and ALA % capacity in non-operated facilities 3. Includes RIPET and Ferndale.

Our Plan: Leverage our core assets and competencies to capitalize on macro North American trends.

This includes leaning on our well-positioned NEBC processing and fractionation footprint and structurally advantaged west coast LPG export platform.

NGL Extraction & Fractionation

64,000 Bbls/d2

6 Facilities: North Pine, Harmattan, EEEP, JEEP,

PEEP, Younger

§ Multiple interconnects with AltaGas existing footprint; Positions AltaGas with increased touch points across the energy value chain.

§

Provides enhanced optionality for AltaGas' customers and producers across the basin to optimize price realizations and realize improved cash flow from production.

§ Four distinct specialized trucking and liquids handling businesses (Millard, Express, Petrogas Logistics and IXL).

§ Includes hauling LPGs, crude, drilling fluids and produced water.

§ Access to 3,000+ car fleet; ~1,750 are pressurized for C3/C4 usage. Various optimization opportunities across broader AltaGas and Petrogas platform.

§ Above and Underground storage of ~6.2 MMBbls.

§ Located in Ferndale, WA, Fort Sask, AB,

Sarnia, ON, Strathcona, AB, Griffith IN, plus other smaller facilities.

• § >50 MBbls/d of combined propane and butane export capacity.

• § Refrigerated LPG storage.

• § Pipeline connected to BP Cherry Point & Phillips 66 Ferndale refineries.

• § Products shipped through the Petrogas-owned wharf, rail, truck and pipeline.

§ Positions AltaGas to leverage its industry-leading footprint in NEBC to grow alongside large industry-led growth initiatives associated with condensate supply supporting oil sands production and long-term feedstock for LNG Canada.

§ Continues to position AltaGas'

Midstream platform for where we believe the market is heading over the next three to five years.

Petrogas: How the Assets Fit Into The AltaGas Value Chain

Integrated Midstream Business - Unparalleled access from wellhead to global markets; including Asia, North America and WCSB

2.25Bcf/d1 Processing 12 Facilities: Townsend, Aitken Creek, Nig Creek, Harmattan, Gordondale, Blair Creek, EEEP, JEEP, PEEP & Younger

NGL Extraction & Fractionation

64,000 Bbls/d2

Transportation, Storage &

Petrogas Enhances AltaGas' Value Chain

7 Facilities: North Pine, Harmattan, EEEP, JEEP, PEEP, Younger

Sales: Local and U.S. Markets

• § Multiple interconnects with AltaGas' existing platform; leaves AltaGas touching increased molecules across the value chain.

• § Increased scale and multiple paths to market enhance flow assurance.

• § Provides enhanced optionality for AltaGas' customers and producers across the basin to optimize price realizations.

• § AltaGas estimates there to be an opportunity for ~$30 million of annual synergies focused on optimizing marketing contracts and logistics, together with supply chain efficiencies and potential cost savings.

• § Plan to take steps to achieve the bulk of these synergies in the first

year and be fully realized on a run-rate basis at the end of 2021.

Better access to Ft. Sask LPG Supply

3,000+ rail cars;

FSK rail and truck terminal, Sarnia and Strathcona terminals, Griffith storage facilities, and truck transportation

To N. American Markets: Transportation of LPG, crude, including Production of other fuels

RIPET Export

Global Markets

1,700 rail cars;

Townsend Truck Terminal, rail terminals, NGL pipelines; treating, storage

Fort Saskatchewan Local Blending

• 1. Based on AltaGas working interest capacity in FG&P and extraction.

• 2. Based on AltaGas 100% working interest facilities and ALA % capacity in non-operated facilities.

• 3. Includes RIPET and Ferndale.

  See "Forward-looking Information"

The Road Ahead will be Paved with Integration and Optimization

• § Enhancing AltaGas' value chain with Petrogas' midstream infrastructure, logistics and services offerings will extend and strengthen the company's integrated platform, offering material value-added benefits for AltaGas' producer suppliers and end-use customers. This will include: 1) expanding AltaGas' logistics capabilities with a significant, complementary asset base in key regions across North America; 2) providing greater access to liquids supply to support these optimization activities; and 3) adding a large network of customer relationships across North America,

  Synergies:

  along with operational expertise in each market.

• § We estimate, in the short-term, there to be approximately $30 million of annual synergies within the combined platform, including supply chain efficiencies, market optimization, strategic positioning and other cost savings opportunities. In the longer term, the addition of the Petrogas assets will position AltaGas with the opportunity to make investments to facilitate the full utilization and capacity of our combined platform to export additional LPG cargoes to Asia.

  Growth:

• § Petrogas has a long history for increasing LPG exports for limited capital outlays. AltaGas will continue that focus, including: 1) leveraging the shipping advantage relative to other facilities (11 days to Asia vs. 25 from the U.S. GC); 2) the continued strong growth in global LPG demand expected over the coming decade; and 3) providing a home for the excess NGL supply that will come from the Montney as LNG Canada increases volumes.

AltaGas-Petrogas Synergies

WCSB Propane Forecast

Global Propane Demand

Global Butane Demand

200

Supply Chain

Efficiencies

Market

Optimization

Strategic

Positioning

Other Cost

Savings Opportunities

MillionMetrictonsperYear

180

160

140

120

100

80

60

40

20

0

200

180

MillionMetrictonsperYear

160

140

120

100

80

60

40

20

0

AsiaAfricaUS/CanadaLatin AmericaMiddle EastEurope

CISPacific

AsiaAfricaUS/CanadaMiddle EastLatin AmericaEuropeCISPacific

Source: IHS Markit, WoodMac, company reports

Strategic Plan and 2021 Outlook

Building a Track Record of Delivering on our Commitments

2019: A Transformational Year

2020: Strong Execution and Focus

2021+ Long-term Vision and Strategy

Refocused AltaGas on core Utilities and Midstream businesses, which are positioned to create durable long-term value creation.

Resilient and durable results expected to be within guidance ranges, despite COVID-19 global pandemic.

Executed ~$2.2 billion of non-core asset sales and balanced funding plan to reduce debt by $3.0 billion and maintain an investment grade credit rating.

Advanced distinct energy export strategy through increased utilization at NEBC facilities, higher RIPET export volumes and increased ownership in Petrogas.

Operate a diversified low-risk, high-growth Utilities and Midstream businesses focused on delivering resilient and durable value for our stakeholders that compounds over time.

Improve quality of life by safely and reliably connecting customers to affordable sources of energy for today and tomorrow.

Achieved results at the top end of the guidance, delivering 26% Y/Y EBITDA growth. Strong results underpinned by growth in core Midstream and Utilities businesses.

Advanced integrated Midstream and energy export strategy with the sanctioning of RIPET, connecting Western Canadian producers to premium LPG markets in Asia.

More timely recovery of expenses and capital at the Utilities through combination of capital discipline, rate case filings and closing the ROE gap at WGL by ~150bps through operational excellence.

Consistently deliver above-average and highly visible growth; focus on trying to create consis-tent "Dime for a Dollar" returns for our investors.

Integrated WGL and updated Michigan and Maryland rates to reflect US$47 million in base rate increases.

Delivering ~$900 million self-funded capital program. Continue to de-lever the balance sheet, maintain investment grade credit rating and stagger, extend and de-risk AltaGas' capital structure and maturity profile.

Operate a safety-focused, digitally-enabled utility that achieves approved returns, exceeds customers' expectations and will excel in an emerging energy ecosystem.

Operate a world class Midstream business that connects producers to domestic and global LPG markets. Provides cleaner burning LPGs to Asia and reduces global emissions.

Operate with acute capital discipline and focused on full-cycle rates of return.

See "Forward-looking Information"

Executive Summary of Strategic Plan

High-level

Views:

Despite market turmoil, we continue to believe that we have a clear plan for an opaque world. While we recalibrated some of our near-term assumptions to reflect shifts in the macro market, our forward playbook remains relatively unchanged.

Utilities:

We continue to have strong multi-year growth potential through new rate base and closing the ROE gap at our underperforming jurisdictions. While COVID has created challenges, we remain steadfast in the need to make this happen as soon as possible.

Midstream:

The Midstream segment is performing well, considering market conditions. Our thesis to build a leading-market position in Northeastern B.C. continues to play out. We remain focused on the long-term opportunity, meeting the needs of the top-tiered operators that we serve, and we'll leverage organic and inorganic capital deployment opportunities at appropriate times.

The Road Ahead:

The road ahead will be paved with acute capital discipline, a heightened framework around risk-management and a strong emphasis on creating an enduring platform that is fueled by operational excellence. We will be pragmatic about reducing our leverage ratios and we will not deviate off course.

See "Forward-looking Information"

2021 Outlook Unchanged

Strong Growth in Base Business Underpins 2021 Outlook

2021 Normalized EBITDA1 Guidance2

($ millions)

$1,400 - $1,500

2021e

Utili ti esMi dstreamCorp/Other

1. Non-GAAP financial measure; see discussion in the advisories See "Forward-looking Information".

2021 Normalized EPS1 Guidance2

(per share)

$1.45 - $1.55

2021e

2021 Normalized EBITDA1 Drivers

Normalized EBITDA1

Growth Drivers

• ▲ Revenue and rate base growth through disciplined capital allocation and rate cases

• ▲ Achieving higher returns on equity through operational excellence

• ▲ Cost-reduction initiatives and decreasing leak rates

• ▲ Customer growth

• ▲ Integration and optimization of Petrogas

• ▲ Higher global export volumes

• ▲ Increasing volumes at North Pine and Townsend

▼ Lower commodity prices, frac spreads and realized margins

▼

Accounting impact on previous blend and extend (signed in 2018; impact taking place in 2021)

2021 Normalized EBITDA1 Guidance

$1.4-$1.5 billion

2021 Operational Review

Midstream: Leveraging our core export strategy

• § Optimize and increase utilization at existing facilities

• § Optimize and integrate Petrogas, significantly expanding integrated Midstream and energy export capabilities

• § Leverage export first-mover advantage to attract additional volume to combined platform and continue to de-risk the business with focus on earnings durability

Utilities: Leveraging our core distribution footprint

• § Increase utilization of Accelerated Replacement Programs to replace aging infrastructure and reduce our environmental footprint

• § Focus on continuous improvement in customer experience and satisfaction

• § Reduce incoming leak rates to lower operating costs and benefit customers

Growth in core business more than offsets lost EBITDA from asset sales, lower frac spreads and other one-time tailwinds that were seen in 2020 and are unlikely to be repeated in 2021.

2021 Normalized EBITDA1 Growth ($ millions)

MMididssttrreeaamm

2020EUtUili ti leitsieGsrowth

Growth

GGrrowtth

§ § § §

DC & MA Rate Cases

ARP Spending

Cost Management

Customer Growth

§

AOsstehteSraYle/Ys Headwinds

AOstshetr SY/aYles Headwinds

Increased ownership of Petrogas

§ §

RIPET Volumes

Higher NEBC throughput volumes

• § ACI

• § CES

• § Pomona

• § Ripon

• § Brush

§ § §

Lower frac spreads

WGL Pension accounting changes

Impact of Blend and Extend (signed in 2018; impact taking place in 2021)

20210EE

• 1 Non-GAAP financial measure; see discussion in the advisories

• 2 Based on mid points of 2020e and 2021e guidance

See "Forward-looking Information

2021 Disciplined Capital Allocation

Strong organic growth drives robust risk-adjusted returns

~$910 million in top-quality projects anticipated to drive earnings growth

Identified Projects: § Nig Creek Expansion § Growth/maintenance

Corp/Other2%Identified Projects:

• § Accelerated Pipe Replacement (ARP) Programs in Michigan, Virginia, Maryland and Washington, D.C.

• § Customer growth

• § System betterment across all Utilities

Capital Allocation Criteria:

Risk-adjusted returns exceed hurdle rates, which includes base hurdle rates, a value creation hurdle and required margin of safety to match risk parameters

Strategic fit that has the prospect of continued organic growth

Provides long-term earnings and cash flow durability

Strong commercial underpinning and continue to leave AltaGas positioned for where the market is heading

Reasonable cash-on-cash payback periods that does not leave the risk of stranded or long-term non-productive capital

See "Forward-looking Information"