Developers planning to build in DeKalb and elsewhere in the state might be surprised to face a new law designed to protect hidden archaeological treasures.

According to a city council report by city planning director Mark Biernacki, the state is now beginning to enforce the Illinois State Agency Historical Resources Preservation Act passed in January 1990.

The act requires developers to conduct an archaeological survey on their property if the state agency determines there is a high probability of finding relics. No state-issued permits can be granted before the survey is completed.

“It is my understanding that this agency is getting all kinds of calls from cities like DeKalb saying, ‘If we have to do this, fine,’ but all of the sudden this comes out of nowhere, it seems,” Biernacki said.

The cost of the initial survey, which is paid for by the developers, is $250 to $500 and takes about 15 to 30 days to complete and file, he said. The developer also pays if other surveys are needed.

Biernacki said DeKalb officials and those of most other municipalities were aware that archaeological surveys were required for government development, but were surprised to find the act also applied to private projects.

Mark Mehrer, NIU assistant anthropology professor, said laws requiring surveys for government projects have been around since 1974, but the new private development law might come as a “nasty shock” for builders.

“The developers here in Illinois have just been finding out about it,” said Mehrer, who has been conducting such surveys for the government since 1976.

He said most sites don’t turn up anything during the initial identification phase. However, if artifacts are found on the ground’s surface or discovered in test holes, the state can mandate a second evaluation survey.

The evaluation survey determines how large and deep the site is, as well as what cultural periods are represented, Mehrer said. The state again reviews the data and may call for a third study to decide how damage to the site can be minimized, he said.

Although the new law might come as a surprise for private developers, “I think it’s a real advance in the way people are learning to take care of their historic and prehistoric sites,” Mehrer said.

With so much development taking place in northern Illinois, “archaeological sites often go under the bulldozer,” Mehrer said.