Ever wonder why your neighborhood streams and rivers look so muddy after a heavy rain? A recent survey of construction sites in the Baltimore area found less than a quarter of the exposed soil being worked had been properly protected from erosion.
The survey, involving staff and volunteers from 22 different environmental and community groups, found widely varying but generally poor controls on mud pollution being used at building sites in Baltimore City and the five surrounding counties.
Mud pollution damages the health of streams, rivers and the Chesapeake Bay by smothering fish habitat and preventing the growth of underwater grasses. Sediment runoff also carries other pollutants, including fertilizer and other plant nutrients that feed algae blooms and dead zones in rivers, lakes and the bay. Maryland and other bay watershed states have been directed by the U.S. Environmental Protection Agency to reduce sediment pollution.
To cut down on sediment pollution, exposed soil needs to be "stabilized" to prevent it from being washed away by rainfall runoff, according to Richard Klein, an environmental consultant from Owings Mills who coordinated the survey. Stabilization is as simple as covering bare ground with straw mulch or grass. Stone also should be placed along roads and parking lots to keep mud from getting on pavement and into storm drains.
Too often, though, contractors are only required to erect plastic "silt fences" around construction sites or excavate ponds to capture runoff. Studies show those only manage to keep 40 percent of mud from running off the site, Klein said.
Rates of soil stabilization at construction sites varied across the region, the survey found. Sites in Anne Arundel, Baltimore and Carroll counties were doing the least to prevent mud pollution, according to the survey, with 12 to 19 percent of soils stabilized. Klein declined to provide individual rates for the three worst-performing counties, saying stabilization was so similarly low in each that it would be unfair to rank them.
The best mud pollution protections were found in Harford. But even there, just 37 percent of exposed soils at construction sites were deemed stabilized. In Baltimore city and Howard, 27 percent of bare ground was properly covered, the survey found.
Based on the survey, Klein estimated that as much as 89 percent of the bare ground seen could have been effectively stabilized.
Klein said discussions with local government inspection chiefs and a review of staffing and enforcement actions by city and county agencies in charge of policing construction sites did not provide any clear explanation for why mud pollution control rates varied as they did.
"We suspect that a major factor could be the importance local administrations place on achieving a high level of compliance with erosion and sediment control laws," the report said. Some local agencies in charge of policing construction sites appeared to lack sufficient staff or enforcement tools, it added.
The Maryland Department of the Environment has reviewed the Baltimore area localities' enforcement of sediment and erosion control and found some shortcomings, but apparently not enough to take enforcement action, according to MDE documents provided by Klein.
MDE spokesman Jay Apperson said the department intends to tighten its oversight of local sediment and erosion controls through new storm-water management permits it is issuing for the state's largest localities, including all those in the Baltimore area.
Meanwhile, he said state officials have been working with EPA to develop "clear criteria" for identifying noncompliance. Under the storm-water permits, Apperson said, local governments found not adequately enforcing mud pollution controls could be fined up to $50,000 per violation.
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Only two local governments responded to a request for comment on the survey.
"We are glad to be ahead of the curve among Maryland jurisdictions, but clearly there is much room for improvement," said Jeff Raymond, spokesman for Baltimore city's Department of Public Works.
Raymond said the city is training its inspectors to focus on stabilizing construction sites and checking the projects included in the survey to see what - if any - violations were issued.
Harford County spokeswoman Sherrie Johnson said officials there intend to review and discuss the survey results "in order for the department to improve our program."
Officials in Baltimore, Carroll and Howard counties did not respond to a request from The Baltimore Sun for comment on the survey. Klein said Carroll officials had questioned the survey methods, but provided no specific objections.
Even so, Klein said the survey appears to have yielded results in at least one jurisdiction. One of the poorly controlled construction sites found in Baltimore County was corrected after county officials were provided the survey results, he said.
And recently, Klein said, an MDE inspection prompted by him led to Baltimore County ordering remediation of what Klein described as 14-year-old erosion problems at Nottingham Ridge, a partially developed 83-acre site in the White Marsh area of Baltimore County.