LYNN – A 44-year-old engineer and Lynn resident is Mayor Judith Flanagan Kennedy?s choice to run the city Public Works Department as it prepares to help local residents make major changes in the way they throw away their trash.Kennedy has asked City Council members in a letter to appoint Andrew J. Hall as public works commissioner effective July 1. Under the City Charter, the appointment is subject to council approval. Ward 7 Councilor Rick Ford said he knows Hall and likes him.?I?ve worked with Andy on a whole bunch of projects. I think he?ll be good,” Ford said.Water and Sewer Commissioner Walter Proodian also praised Hall as “capable” and “efficient.”He recalled how Hall – who is the commission?s senior engineer – personally investigated a leak in a sewer pipe near Jackson Street after previous attempts to find the leak?s source were unsuccessful.?He walked a whole block underground and found a broken pipe,” said Proodian.Hall called the mayor?s nomination “an opportunity that presented itself” and said he welcomes the chance to hold a city leadership position.?It?s more responsibility – that excites me,” he said.Hall has a master?s degree in engineering from Northeastern University and has worked for Lynn Water and Sewer since 1996. He is married and has three children.After learning Kennedy had nominated him to be the next DPW commissioner, he drove his family down to public works? Commercial Street complex, where the industrial surroundings contrast with Water and Sewer?s hilltop headquarters with its view of Lynn Woods.?DPW is the engine room of the city,” Hall said.He once drove a plow for the city, but Hall?s responsibility – subject to his nomination receiving council approval – include answering councilors? questions about the department?s workforce and equipment needs and helping the city?s 28,000 households make the transition to automated trash collection.Waste Management, the city?s trash collector, is making the switch in October under a five-year contract aimed at boosting household recycling and cutting costs associated with burning Lynn trash in the Wheelabrator incinerator. Instead of placing barrels curbside for pickup, residents will put trash and recyclable items into wheel-mounted bins provided free by Waste Management.Hall said the transition will partly involve educating older city residents about recycling?s merits and the relative ease involved in doing it.?My family recycles more than we throw away,” he said.Councilor at large Hong Net is looking forward to meeting Hall.?I need to see he is willing to work with the City Council to make, as his top priority, what residents want,” Net said.If his nomination wins council approval, Hall will be the city?s third DPW chief in a year. Former Commissioner Manuel Alcantara retired last June and Kennedy named former town of Hopkinton public works director J.T. Gaucher as acting interim commissioner.The charter requires the commissioner to hold a three-year contract, and it gives the commissioner authority to reorganize the department, subject to mayoral and council approval. The charter also contains this warning to elected city officials: “…neither he (sic) nor any committee of the city council shall in any manner attempt to become involved in the scheduling of work assignments to employees or otherwise interfere with the day-to-day operation of the department.”