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Plan of Study for City of North Olmsted Phase I by Floyd Browne Group January 4, 2006 where they discharge to. Some of these homes are experiencing basement flooding and should be investigated further. The residential home surveys were obtained in the same manner as in the LeBern Service Area. Residential Inspections The residential inspections were very helpful and revealing. Many of the residents do not know where their foundation drains connect. During the August 20`h storm, flooding occurred in many areas, but in this report, we have tried to focus on the areas where many people were flooded. There are some isolated cases that should be investigated on an individual basis to identify the specific problem such as a clogged lateral, lowest house in the area, etc. In this study, we have tried to give an overview and summarize some of the major issues affecting the proper operation of the sanitary sewer system. Observations and residential surveys revealed that a few backups were due to the sanitary sewer and that most were due to the storm water entering the basements. Many of the downspouts have been disconnected from below grade and use splash pads around the house foundation. Some flooding in the yards would indicate that storm water is getting into the foundation drains and then into the sanitary sewer. The downspouts for all of the homes in the area should be dye tested and repaired if necessary to convey the roof water to the storm water system. The Blossom and Edgepark Blvd. basement flooding appears to be a result of the backup at the Dover Pump Station. However, storm water flooding and foundation drain inflow contributed to the problem. The Hyannis Port, Williamstown, and Leenders area flooding seems to be the result of excessive storm water and flooding from the drainage ditch in the rear of the properties. Most of the flooding in the Dover Service Area appears to be from localized storm water problems. A partial blockage in the mainline sanitary sewer may have contributed to the problem. This line has been cleared and is now operating properly. Further investigation is necessary to determine the effects of the sanitary sewer system on the basement flooding. Sanitary Sewer System Evaluation and Analysis The sanitary sewer system tributary to the Dover Pump Station consists of a 15-inch diameter trunk from the east and a 21-inch trunk from the west. Most of these sewers are at minimum grades to comply with the scouring velocity requirement of two-feet per second. The local sewers are 8-inch diameter with some 10-12-inch collector sewers. This system was installed in the 1960's to eliminate septic tanks and some small wastewater package plants as well as to provide for future development. The sewer lines are mainly vitrified clay pipe in 4-6 foot lengths. The Dover Pump Station operates on a variable frequency drive that keeps the level in the wet well constant while increasing the pumping rate as the influent flow rate increases. Normal Average Daily Flow (ADF) is approximately 1.35 million gallons per day (MGD) or 940 gallons per minute (gpm). The station can handle a peak flow of approximately 4 MGD or 2775 gpm when all three pumps are utilized. Based on 2700 residential equivalent units (REUs), the design flows would be an ADF of 1.08 MGD and a PDF of 3.61 MGD. Due to the poor soils and the shallow rock elevations, the ground water table must be somewhat high and contributing 15