ABERDEEN -- A second test of a Harford County well has confirmed the presence of a hazardous chemical in the well field, Aberdeen Proving Ground officials said yesterday.

The test found a level of 0.3 parts per billion of perchlorate in production well No. 9, which is on APG's western boundary in Perryman, said George Mercer, APG spokesman. No perchlorate has been found in the drinking water, county officials said this week.

Mercer said the perchlorate test was done because of the discovery of the chemical, a component in rocket fuel and incendiary munitions, in the city of Aberdeen's wells nearby. Base officials said the two areas of contamination don't appear to be connected, but research is under way to try to better determine past uses of the two areas. The county and base are discussing whether to begin regular tests of the Harford well field for perchlorate, Mercer said.