Investor Presentaiton

Significant Energy Infrastructure Platform High-quality, contracted assets with attractive organic growth ~2 Bcf/d1 of Natural Gas transacted ~70,000 Bbls/d liquids produced 1,690 Mmcf/d of extraction capacity ■ ~900 Mmcf/d of FG&P capacity 2 export terminals² Interest in four major pipelines in Marcellus / Utica 1,930 MW of Power Generation 1,259 MW Gas 277 MW Hydro 117 MW Wind 35 MW Biomass 20 MW Energy Storage 222 MW Distributed Generation ~$5B3 Utility Rate base ~1.8 million customers 8 Jurisdictions Alberta, B.C. and Nova Scotia in Canada Alaska, District of Columbia, Maryland, Michigan and Virginia in the U.S. ~75% U.S. normalized EBITDA contribution ~25% Canadian normalized EBITDA contribution ~80% normalized EBITDA contracted with medium and long-term agreements 1 AltaGas only; 2 AltaGas' 1/3 Ownership in Ferndale, and 70% Ownership in Ridley Island Propane Export Terminal; 3 AltaGas expectation as of December 2017, WGL extrapolated to calendar year end 2017 based on FY2017 rate base and a CAGR of 9.0%, US dollars converted C$1.26/US $1.00 AltaGas * Expectations as at August 1, 2018 ** Normalized EBITDA is a non-GAAP Financial Measure See "forward-looking information" 4

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