Stormwater report discussed here

Friday, September 28, 2012

By Karen Hall

Staff Writer

A public hearing was held, as required, by Lewisburg's stormwater department in the City Hall Wednesday, but no members of the public attended.

The hearing was to review the annual report of the Small Municipal Separate Storm Sewer System (MS4), covering the year from July 1, 2011, to June 30, 2012.

"It's kind of odd" that a public hearing is required, said engineer Jim Patterson. "There's nothing the public could say. We can't change what we did last year. It is what it is."

Nevertheless, Patterson and Stormwater and Codes Director Joe "Buck" Beard met in Beard's office and discussed the current stormwater program, and changes coming in the near future.

The city's stormwater program, which became a federal requirement when the population exceeded 10,000, has several parts.

One is the regulation of construction projects to keep sediment and loose dirt on the site, instead of letting it flow away with the rain water into storm drains, or into creeks or ponds.

Another is education of school children, the general public, and builders. Beard has held meetings with local contractors and he distributes educational materials to elementary schools. Public service announcements about stormwater are placed on the radio and in the newspaper.

Beard also spends time on an illicit discharge detection program. The report states he has completed a map of all outfalls and receiving waters of Lewisburg's storm sewer system, and identified 294 outfalls. Of these, 172 have been inspected during dry weather in the last year. In the year covered by the current report, no illicit discharges were found.

Six notices of violation at construction sites were handed out by Beard during the reporting period, and most related to improper sediment and erosion-control measures. According to the report, the sites were brought back into compliance without recourse to more extreme measures like fines, stop-work orders, civil penalties or criminal actions.

The stormwater program is financed from the city's general fund, at a cost of about $56,000 per year. Some cities have an independent financing mechanism for their program, such as stormwater fees.

The handling of stormwater quality and quantity issues after the construction of new developments is about to change dramatically, according to Patterson.

In about two years, planners and developers must start implementing "green" infrastructure. For instance, new developments must show no runoff at all after the first inch of rain.

"This is not simple to accomplish," exclaimed Patterson.

Some of the ways to achieve this goal include having less runoff to begin with. One way to do this is to have less impervious (paved) area. This can mean narrower streets, shared driveways, and more trees and grassy areas.

Stormwater detention basins can hold excess rainwater and let it trickle slowly into the ground. In wet weather, a detention basin will look like a pond; the rest of the time it will be a grass-lined dip in the ground.

Rain barrels, capturing the water from a house's gutters and saving it for future use, are another way to minimize runoff. Patterson added a note of caution here: if the city decides to allow rain barrels as part of a development's stormwater control system, the city will then have to monitor the barrels to make sure they remain functional.

Another good way to reduce runoff is with rain gardens, designed to receive excess water and percolate it through a series of soil or gravel layers beneath the surface plantings to the groundwater. The plants for a rain garden are typically native to the area and include a selection of wetland edge vegetation, such as wildflowers, sedges, rushes, ferns, shrubs and small trees.

"The city's a good ways away from incorporating any green infrastructure requirements," Patterson said. "The planning commission will have to look real closely at changes to subdivision regulations. There's a lot that can go into this."

He added there's a lot of talk about gray-water usage, in other words, reusing water from baths, showers, washing machines and dishwashers to flush toilets.

"That's the way the EPA is definitely pushing cities to go," Patterson said, but it will require rewriting plumbing codes, and careful inspection to make sure the potable water and gray water systems are kept completely separate.

The engineer predicted in the near future Lewisburg residents will see a reduction of stormwater runoff, accomplished through a combination of infiltration and reuse.