*For the fifth consecutive year, Prince William County has won the Certificate of Achievement for excellence in financial reporting from the Government Finance Officers Association, a national organization. The award was based on the county's annual financial report for 1985.

County Executive Robert Noe credited acting finance director William Hoffman and his staff for the award, citing their "continuing efforts to compile and communicate Prince William's financial status to the public." The association will also honor Hoffman, a six-year county employe, with an individual Financial Reporting Achievement Award, Noe said.

The winning report, a 184-page document, covered the financial activities of more than 40 different funds, including county schools and several independent agencies.

*Some administrative offices of Prince William County's public schools were moved last week from Tudor Lane to Independent Hill, just outside Manassas off Route 234. The move consolidates offices in one location, spokeswoman Kristy Larson said.

Most of the school telephone numbers in the county directory will remain the same, except those with a 369 exchange. Those numbers will now be in the 791 exchange; the last four digits will remain the same, Larson said.

*A new book by Larry Davis, a national authority on firefighting, highlights methods used by Prince William firefighters, county spokeswoman Susan Mack said.

The book, titled "World Firefighting Operations," reports on a technique that county firefighters use to pump water at a faster-than-normal rate from a water source such as a pond by transferring the water to portable tanks, from which it is delivered to the fire by a larger pumper. The book also includes several Prince William photographs, Mack said.

She said Davis learned of the technique when he taught the department a course on water supplies two years ago.

*The Prince William Scholastic Association will hold its annual regatta at Sandy Run Park at 11 a.m. Saturday. For information call the Prince William Crew Association at 491-3298 or 590-4245.

The county's swimming pools will open Saturday at the Veterans, Birchdale, Hammill Mill, Graham and Ben Lomond parks. For information call 670-9118.