Exhibit 99.1 October 29, 2025 Investor Contact: Aaron Musgrave Vice President, Investor Relations 856-955-4029 aaron.musgrave@amwater.com Media Contact: Maureen Duffy Executive Vice President, Communications and External Affairs 856-955-4163 maureen.duffy@amwater.com AMERICAN WATER REPORTS STRONG THIRD QUARTER 2025 RESULTS AFFIRMS LONG-TERM TARGETS AND 2025 EPS GUIDANCE INITIATES 2026 EPS GUIDANCE, REFLECTING GROWTH OF 8% ANNOUNCED MERGER WITH ESSENTIAL UTILITIES; EXPECTED CLOSING Q1 2027 CAMDEN, N.J., Octo ...