Firm Says: Millburn May Flood Again
Engineering firm, Hatch Mott McDonald, presented the committee with a study that says the township needs help from surrounding towns to prevent flooding.
In the Millburn Township Committee meeting this week, Hatch Mott McDonald, an engineering firm, gave a presentation of a study it conducted to find a way to prevent flooding in town.
However, after researching the issues since the January of this year, the firm, which specializes in storm and sewer water management, said Millburn can't fix the issue alone.
"The problems are much larger than we thought they initially might be," a senior vice president of Hatch Mott McDonald, John Rolak Jr. said.
The study showed six municipalities' sewer lines, New Providence, Summit, South Orange, West Orange, Maplewood and Millburn, all meet at Gilbert Place pump station and go under the Rahway River and Route 78 to the treatment plant in Elizabeth.
"The biggest problem is there is too much flow and not enough capacity," Rolak said. A large reason for the overcapacity is an inflow and infiltration of the sewer systems the Rolak explained.
Inflow and infiltration is surface and underground water that seeps into the sewer system. Surface water could be cause by a heavy rain fall that flows into the manholes and therefore into the sewer system. Underground water can come from cracked pipes caused by tree roots or just age.
"There's a lot of different problems that need to be handled separately," Mayor Sandra Haimoff said.
The committee said, Millburn has inspected all the pipes that the township owns and according to the study Millburn only adds 5 percent of water from inflow and infiltration. So, without the help of contributing towns Millburn doesn't have much of a feasible solution Gordon said.
Gordon explained, after the meeting, the regional sewer organization, the Joint Meeting of Union and Essex, consisting of 11 municipalities that all have a voting representative, could vote on regulations to control inflow and infiltration. If a township did not meet these regulations the township would be fined.
Out of the six municipalities contributing to this problem, West Orange has the highest percentage of inflow and infiltration, at about 27 percent.
According to study, the reason why sewage comes up through the manholes near Ridgewood Road and Locust Place is due the low ground level at that point, the lowest in the pipeline.
Engineer John Dening of Hatch Mott McDonald said when there is over 4.5 inches of rain in 24-hour period it backs up in Union, on the other side of route 78, and comes back into Millburn.
A resident from the Ridgewood Road and Locust Place area in attendance agreed, saying during Hurricane Irene, sewage was coming up through the manholes before water from the storm actually flooded the area.
The firm said this type of rainfall only happens every five years.
One proposed solution was to seal the manholes in that area. However, Rolak said it would just push the problem further up the line and it would come up somewhere else.
Another proposed solution was to replaced the pipe with one that could handle more capacity but that comes with a very high price. Eight miles of the pipe would have to be replaced and the treatment plant would have to be upgraded, which all towns on the line would have to agree to.
The committee discussed possible regulations throughout town to reduce inflow and infiltration but agreed the issue will have to be revisited.