At an unusual press conference yesterday, Montgomery County Public Schools Superintendent Charles M. Bernardo defended his record over the past year and criticized a county teacher's union official for spreading "scurrilous . . . political hogwash" about him.

Bernardo called the press briefing at a time when his stewardship of the school system is under review by school officials deciding whether his $53,000 annual contract should be renewed.

By outlining his plans for the future and dismissing his critics, Bernardo made it clear that he wants to stay on in the county and win contract renewal this September.

"I came to Montgomery County (from Providence, R.I. with an outstanding education career behind me and I intend to continue it . . . I have no question about my continuance in the county," Bernardo said.

But at his press conference, Bernardo had to defend his often-controversial policies. It was, in effect, the opening volley of what is expected to be a heated debate within school circles during the next fewmonths.

Many of the "priorities" Bernardo outlined for the upcoming school year are the same ones he set last year, but he plans to expand many of the existing programs.

For example, the schools will continue to monitor the progress of pupils in reading and math to ensure that students are mastering these basic skills, but such a monitoring program will be expanded to include science and social studies.

Bernardo said he intends to lower the age to 5 at which a student may enter the first grade. He also plans to increase the number of courses for which students can earn high school credit by taking examinations instead of sitting through the courses in class.

Bernardo called "hogwash" charges made by Henry B. Heller, president of the Montgomery County Educators Association, that Bernardo and hired a personal friend to do $36,620 worth of consulting work over the past three years in violation of school board policy. Heller has claimed that such contracts required competitive bidding.

Bernardo said Heller is wrong, that unlike contracts for jobs like those performed by bricklayers, for instance, competitive bidding is not required for consultant work. He said all of the work done by William Pepper, the consultant in question, had been approved by the school board.

"The issue of my personal integrity is so important to me that people who (make such statements) do this at the risk of legal action.I think Hank (Heller) is treading on dangerous ground," Bernardo said after the press conference.

Opposition to Bernardo's administration has been strong among the educators association which represents 4,800 teachers of the 7,000 in the system. Bernardo's programs and decisions are made in "secret" with information gathered by "outside consultants" who never speak with experienced personnel in the system, Heller has complained.

Earlier this month, Heller asked school board president Elizabeth Spencer to "fully investigate" the relationship between Bernardo and Pepper. He also circulated copies of an article published in an out-of-town newspaper which made allegations against Pepper.

Spencer said yesterday that she plans to appoint an outside consultant to look at the allegations.

Defending the programs and policy changes he has initiated, Bernardo said, "the record will show I've achieved the objectives mutually agreed upon by the Board of Education . . . I have . . . for the most part performed a job well done."

Bernardo asserted that in his three-year tenure, discipline and attendance in schools has improved. He also said that test scores have risen and racial problems subsided.