Ladd Gibson was expecting a contentious hearing at Polo Road Elementary School Tuesday night.
The program manager at the South Carolina Department of Transportation knew northeast Richland County residents were unhappy with new plans to expand Interstate 20.
“We’re going to hear a lot about that wall tonight,” Gibson said.
“That wall” is a sound barrier to be built along parts the interstate once it expands to six lanes in a nearly seven-mile stretch from the junction with I-77 to Spears Creek Church Road. The SCDOT’s guidelines state that anytime the noise of a new highway approaches or exceeds 67 decibels (dBA), a sound barrier must be considered.
Once a barrier is considered, the department uses guidelines to determine if such a wall is “reasonable.” Among other factors, the SCDOT uses a cost-effectiveness ratio. The ratio is created by taking the estimated cost of the wall and dividing it by the number of “benefitted receptors,” or the number of homes, apartment units, or businesses where the level of highway noise decreases by at least 5 decibels due to the wall. For South Carolina, the ratio is $25,000 per benefitted receptor.
Several neighborhoods north of the interstate did not reach the necessary cost-effectiveness, Gibson said. The SCDOT’s environmental impact statement said a wall in that area would cost over $33,000 per receptor.
Gibson’s prediction proved accurate. Hundreds of residents from the Wildewood, Enclave, and Belleclave neighborhoods appeared at the hearing. Nearly all of the complaints concerned the lack of a wall for a 1.5 mile stretch in front of their homes.
Danny Clayton said his property is only a few hundred yards away from I-20. He said the ratio should not be the deciding factor, saying it’s only meant as a guideline. He pointed out that the ratio does not account for the number of people involved, only the number of structures.
Per person impacted is being looked at as an objective guideline that is hard and fast, (they’re) not following their own guidelines saying that this is just a general, and not all-encompasing measure. Is it reasonable to count both (Polo Road) Elementary School and Chesterbrook Academy as one beneficiary?
He also said the guideline marks apartments as individual units but only counts houses as one “benefitted receptor.” He called it unfair, adding that those in apartments are less likely to live in the area permanently. SCDOT has said barriers will be installed in front of several apartment complexes along the corridor.
Another Wildewood resident, Sal Dinardi, said the 67 decibel figure was improper.
The World Health Organization has deemed that 55 decibels is the appropriate comfort level, not 67. To give you a difference: 67 is twice as loud as 55.
But Gibson said the SCDOT used the same guidelines it uses for all of its projects. He worried that any changes might set a bad precedent for future proposals.
We felt like we treated everyone along the corridor fairly, according to our policy. Someone may disagree with our policy, but that’s the policy we have right now and we feel comfortable that we followed it to a “T.”
Doug Bridges, a realtor who also lives in the affected area, drew applause after saying the lack of a sound barrier was unfair to his neighborhood.
It’s interesting to me that these four subdivisions probably represent the highest payees of federal taxes of all the people affected by this six mile endeavor.
Officials maintain the proposals are not final and encourage residents to continue to write to the SCDOT to voice their concerns. The deadline for all comments is September 18.
The good news for northeast Richland residents is that the highway construction will have little impact for drivers. Gibson said lane closures will only happen at night, in order to avoid long delays for traffic on I-20. The SCDOT estimates the project will cost up to $90 million and will begin in early 2011. Construction is expected to last almost three years.
Environmental Assesment (PDF. Information on sound barriers begins on page 14)