On August 23, 2010, about 1320 eastern daylight time, a Piper PA-30, N8734Y, owned and operated by a private individual, was substantially damaged when it impacted terrain, during takeoff from Douglas Municipal Airport (DQH), Douglas, Georgia. The certificated airline transport pilot was seriously injured. Visual meteorological conditions prevailed and no flight plan had been filed for the local personal flight conducted under the provisions of Title 14 Code of Federal Regulations Part 91. According to the owner, the airplane had been parked outside at DQH, and not flown for about 1 year. On July 7, 2010, an annual inspection was performed on the airplane, however, during a subsequent test-flight on July 25, the left engine "missed" and additional maintenance was performed, which included "flushing the fuel tanks and cleaning the fuel lines to each respective flow divider." On the date of the accident, the pilot intended to fly the airplane to Florida, where the owner planned to sell it. According to the pilot, during the preflight inspection, he observed water in the airplane's main fuel tanks, and debris in the right wingtip fuel tank. During two subsequent ground-runs, both engines had periods of rough running operation and unidentifiable debris was observed in the fuel injectors. A third ground-run was conducted without any anomalies noted, and the pilot intended to conduct a test-flight in the airport traffic pattern. After normal preflight checks, the pilot attempted to depart from runway 22, a 6,000-foot-long, 100-foot-wide, asphalt runway. During the takeoff roll, the right engine rpm exceeded redline on a digital rpm gauge. The pilot adjusted the engine power and continued with the takeoff. The airplane lifted off the runway and was accelerating in ground effect, when the left engine began to run rough. The pilot believed that there was insufficient runway remaining to land and stop on the runway. He attempted to climb; however, the airplane began to settle and slowly yaw to the left. The airplane subsequently impacted trees, and came to rest about a 1/4-mile southwest of the airport. The airplane sustained substantial damage to both wings, the fuselage, and empennage. The airplane was equipped with two Lycoming IO-360-C1C series engines. The position of the wreckage precluded examination at the accident site. Subsequent examination of the wreckage conducted by representatives of the airframe and engine manufacturers, under the supervision of a Federal Aviation Administration (FAA) inspector revealed the presence of water and corrosion in the fuel distribution system. Water was observed in both of the main fuel tank strainers and the left engine fuel injector. In addition, fuel that was drained from the airplane by recovery personnel contained water and unidentified debris. No additional anomalies were noted, which would have prevented normal engine operation. According to fuel records, the airplane was "topped-off" with 30 gallons of 100-low-lead aviation gasoline on the morning of the accident. Three airplanes were refueled on the day prior to the accident, and one airplane was refueled after the accident airplane. The airport manager reported that he specifically contacted the owners and/or pilots of those airplanes, and they reported that they did not experience any fuel related problems. The pilot reported 3,465 hours of total flight experience, which included 3,297 hours in rotorcraft, 141 hours in single-engine airplanes, and 22 hours in multiengine airplanes. The pilot had no previous experience in the same make and model as the accident airplane beyond the test flight that was performed in July, and the accident flight.