The objective of this project was to determine the roles and synergistic effects of pressure, pressure fluctuations, and hydrotesting on low-pH stress corrosion crack (SCC) growth. The project consisted oth three tasks: 1) to prepare test specimens and experimental apparatus and to establish a standard test protocol for conducting cyclic load tests and analyzing the test data; 2) to evaluate the effects of frequency, R ratio, and waveform on SCC growth in low pH environments; and 3) to evaluate the influence of hydrostatic pipeline testing on subsequent SCC growth in low-pH environments.