Correspondence between

Hello Bob, Mike and Luke, Hopefully you have already received, or will be receiving by July 1° deadline, the LT2 Source Water Monitoring Plans for the 2"¢ round of sampling from the Schedule 2 WTPs in your district (Flint, Wyoming and all the plants getting raw water from the Saginaw-Midland pipeline). The next step is to review them and either approve ‘em, or request missing or incomplete information if some is needed. In order to assist you in reviewing the plans, attached is a Reviewers Checklist that EPA staff used for the first round of monitoring back in 2006. The checklist contains the items that you should be looking for when reviewing and approving the plans. | recommend that you complete the checklist when (and if) you approve the plans and place your name and date in the bottom line and attach it to the plan and place it in the appropriate file for safe keeping. Also attached is a sample letter that you may use to notify the systems that their Source Water Monitoring Plans for the 2nd round of sampling is approved (assuming that you have reviewed and approved them). Please feel free to modify the letter as you see fit. If you have any questions about these issues, please give me a call. Patrick Cook, P.E. Community Drinking Water Unit Office of Drinking Water & Municipal Assistance Michigan Department of Environmental Quality Phone: (517) 284-6514 [email protected] xxxEND_PAGE:deq18_b012_0539_0539_1

Mike, Because the 2009 excwadance occurred under Stage 1, when | refer to “Bay City”, Ernean the entire service area (City rdus customer communities}, We had Bay City sampling both inside and outside the City in order to regresent the system as awhole. Two sites represented maximurn residence tine, and twa represented “at least average residence thre”, which was the criteria for Stage 1. The systern as a whole was out of compllance during the 2" 3 and 4" calendar quarters of 2008, and it returned to compliance during the 1% quarter of 2010. After that, the system asa whole remained in compllance for the rest of the time that Stage 1 was in effect. Since Stage 2 started, only the listed custeyner cornmunities exceeded the MCL. The City of Bay City itself has always been in compliance with Stage 7 Ba 2. Bol London

Bob, lam assuming Bay City re-achleved compliance under Stage | and has maintained compliance ulder Stage 2... Michael Prysby, PLE. District Engineer Office of Drinking Water and Municipal Assistance 547 290-8817

Mike, Populations sarved: Beaver Road Association serves 786 Beaver Township serves 1109 xxxEND_PAGE:deq16_b5_0892_4900_0848 Portsmouth Township serves 525 Buena Vista Township serves 8676 The above are the only systems to exceed the MCL since 1/1/2010. in 2009, under Stage 1, Bay City exceeded the TTHM MCL, with a duration of 3 calendar quarters. Since this occurred under Stage 1, commpllance was based on a system-wide RAS (of four locations} rather than LRAAs. The highest systern-wide RAS during this time was 99.6 gob. twill leave it to you to decide what, if any, of the above information should be passed along. Vrn sure you have a better idea of what, specifically, he is looking for. Bol London

Here are the additional ?s frorn Ron Fonger concerning the systerns that exceeded the TTHM MCL. Michael Prysby, PLE. District Engineer Office of Drinking Water and Municipal Assistance 517 290-8617

Attached is additional detail on the other TTHM MCL violations (how high the LRAA is/was, violation duration). Bob, you should probably verify the accuracy since they are all your supplies.

Looks like we will need some further assistance from you regarding Ron’s first question concerning the occurrence of TTHM’s here in Michigan. Similar question as before...but more detail... Michael Prysby, P.E. District Engineer Office of Drinking Water and Municipal Assistance 517 290-8817