Ald. Raymond Lopez (15), right, and Chicago Department of Water Management Deputy Comm. Joel Vieyra during a City Council finance committee meeting on Monday

Aldermen seized on a technical change meant to save money on water infrastructure projects to lash officials on Monday over what they called an unacceptable slowdown in water department projects. The department is slated to spend hundreds of millions of dollars on pipe replacements this year — but they’re already tempering expectations among procurement hurdles and regulatory red tape.