EXHIBIT 10.21 SECOND AMENDMENT TO CREDIT AGREEMENT THIS SECOND AMENDMENT TO CREDIT AGREEMENT (this "Amendment") dated as of the 19th day of August, 1999, by and among PLAINS SCURLOCK PERMIAN, L.P. ("Borrower") and BANKBOSTON, N.A., as Administrative...Credit Agreement • September 10th, 1999 • Plains All American Pipeline Lp • Pipe lines (no natural gas) • New York
