Are Mosquitoes Exploiting DC’s Building Boom?

Commissioner Rhonda Hamilton (6D06). “I can’t say it’s tied to construction, but every year they grow in numbers.”

The Southwest neighborhood of the District is a busy place. More than 50 development projects are planned or underway in the area, including The Wharf, the new DC United stadium, and a new Pepco station, leading to increased business, residents and excitement.

But some are wondering if all this all new development, combined with a rapidly warming climate will be accompanied by an old problem: a proliferation of mosquitoes and the diseases they could potentially transmit. For with construction comes the mosquitoes favorite breeding place—standing water.

Historically, the District’s waterfront neighborhoods have suffered disproportionately from mosquito-borne illnesses, such as yellow fever, dengue and malaria.

The marshy flats of the Anacostia bred mosquitoes that tormented early settlers. In the nineteenth century residents living in the area around the James Creek Canal called ‘Bloodfield’ had disease buzzing in their streets. The canal flowed through the neighborhood along the current Canal Street SW, down Fifth St. SW to the Anacostia. Sewage flowed into the canals and the creek, blocking flow and creating a breeding ground for mosquitoes, malaria, and yellow fever in addition to cholera and dysentery.

Over time, efforts were made to clear the area of pests and disease. The canals were covered up beginning in 1870, and by 1949 malaria was basically eliminated in the United States by the use of DDT as part of the National Malaria Eradication Program.

But now the combination of the ongoing Southwest development with a quickly warming climate has many asking if one of the largest construction booms in America may bring about a resurgence of one of the smallest flying pests.

John Wennersten, Professor Emeritus in Environmental History at Maryland University and author of The Historic Waterfront of Washington, DC and co-author of Rising Tides: Climate Refugees in the Twenty-First Century says that of the many possible threats climate change poses, virulent mosquito infestations are a distinct – and frightening – possibility.

“The mosquito problem is largely a result of the changes in the climate and now we’re getting mosquitoes that should normally be confined to tropical areas coming into our midst,” he says, “and nobody seems to be that alarmed by it.”

Quality of Life
Andy Litsky is a Southwest resident and Advisory Neighborhood Commissioner (ANC) for the area that includes The Wharf development. He said in light of low-lying lands, such as Buzzard Point, and the multiple construction sites, residents have to be alert to standing water and take measures to reduce it.

“Those of us who live near construction sites have to be aware that if we see pooling water we have to report it to the folks who are doing the construction so that it can be dealt with.”

Commissioner Rhonda Hamilton (6D06), whose single-member district lies just north of the future site of the DC United Stadium, says that the mosquitoes have grown more numerous and more aggressive over the past few years.

“There used to be a time when they’d just bite you in the evening or at night, but these mosquitoes just bite you all day long. These mosquitoes are more aggressive and stay out longer.”

She said that mosquitoes in Southwest are a quality of life issue, preventing folks from sitting on their front porches in the spring and summer to socialize with passers-by. “We can’t even enjoy our yards, or have cook-outs. You can’t just have kids running around in that.”

Unfortunately, however, learning to co-exist with mosquitoes might be the least of our worries. Once thought eradicated, in 2002 the British Medical Journal reported two cases of malaria acquired locally from mosquitoes along the Potomac River.

Hamilton says that she is aware of one elderly neighbor who passed away last year due to West Nile. She is concerned about her mother’s health every time she sits on the porch. Next door to her home last summer a two-year-old child received so many bites it had to be hospitalized.

Litsky said that a few years back, a resident living near the Southwest Duck Pond contracted West Nile disease, and was treated in George Washington Hospital before being released. Abatement efforts have improved since then, Litsky added, but he still hopes for more from the District. “The city’s budget isn’t what I think we would like it to be.”

Christine Spencer, President-Elect of the James Creek Resident Council, agrees. She says that the District’s efforts are insufficient. She is of the opinion that it was the District’s decision to quit spraying for adult mosquitoes that contributed to the problem, considering the tree canopy and harbor for the insects.

“They need to come spray the trees. James Creek is sitting on a creek. What are we supposed to do?”

A Robust Program in Place
It is the responsibility of the Department of Health (DOH) to monitor the transmission of disease in the District. For the past fifteen years there has been a robust mosquito abatement and monitoring program in place.

“I don’t know of any other place in the U.S. that is implementing as thorough a program as we do,” said Vito DelVento, Executive Director of the DOH Animal Services Program.

Of those diseases most commonly associated with mosquitoes, such as Zika, West Nile, Chikungunya and the Dengue Virus, DOH has only identified West Nile in mosquitoes. To DelVento, this is not a surprise. “We know that West Nile is here, has been here and is likely to always be here [in the mosquito population].”

They have also captured and identified a mosquito known as Aedes Egypti, but these potential carriers of Zika make up less than 1% of mosquitoes captured and none have carried Zika or any of the other diseases.

But Delvento said that even if a mosquito were a carrier, all of the factors have to be aligned for a human to be infected. “You‘d have to have someone in the right stage bitten by the right mosquito at precisely the right time for transmission.”

DelVento says the DOH is both aware of and monitoring these conditions. He is, however, cautious.

“The threat [of new disease] always exists.”

Prior to last year, DOH in partnership with DC Water, distributed larvicide only on an as-needed basis throughout the District. But last year, the DOH mitigation program was expanded in light of Zika concerns. Now, DOH treats every District water cistern and known standing water once every thirty days, the potency cycle of larvicide.

The larvicide program generally runs between June 1 and the end of summer, with the option of extending it if there is exceptionally warm weather. The DOH has the lead on the program, but other agencies, such as DC Water and the Department of Energy and the Environment (DOEE), have access to larvicide materials and programs for prevention.

He added that the District no longer uses adulticide, the spray to kill living mosquitoes. The Center for Disease Control (CDC) recommends larvicide rather than adulticide for reasons of economy, environment and efficiency, saying that the latter has limited effectiveness.

Relying Heavily on Citizens
However, DOH has no program for the prevention of mosquito proliferation in construction sites and monitoring seems to fall to residents. DOH does not monitor construction sites nor do they have regular conversations with developers before sites are broken. DelVento said he did not think it was necessary to discuss prevention with developers. “I think it’s fair to say that they have some knowledge of the concerns for standing water in general.”

When asked about mosquitoes, standing water and construction, a local BID representative offered no comment, deferring to DOEE on the subject.

For its part, a spokesperson for DOEE cited the District’s storm water management rules that require the capture and infiltration of storm water runoff within 72 hours. “This infiltration rate does not allow enough time for mosquitoes to breed in ponded water.”

But, the spokesperson added, besides storm water management, DOEE could not really speak to mosquito abatement.

“Mosquitoes are really squarely under DOH.”

DelVento noted that while they have oversight over mosquito abatement, as a sister agency DOEE has larvicide materials they could use and that they were hopefully addressing concerns as they see them.

But resident vigilance is key in the abatement of mosquitoes. DelVento said that DOH relies heavily on citizens reporting standing water, both in residential areas and on commercial construction sites.

“If there is a concern, the DOH team will go out and investigate the situation and talk to general contractors or developers about how we can help them and they can help us minimize standing water as breeding ground for mosquitoes. We do have access.”

While DOH does not talk about mosquitoes with developers, they have spent time and effort teaching residents how to reduce mosquito breeding sites in the community and providing educational materials and mosquito protection kits to DC residents.

Litsky says residents should be reporting standing water no matter where they see it, the same way they would report a fallen tree branch or a pothole. Monitoring for mosquitoes is something residents have to do seasonally, he said, like turning the clocks back.

Citizens can report concerns with standing water to DOH by emailing or by calling 202-442-5955.

Climate Change
At present, the increased threat of mosquitoes and mosquito-borne illnesses has not, from the perspective of District government, required the further expansion of mosquito control programs. But as the climate continues to change, Wennersten says there is no doubt that the mosquito problem will intensify, bringing more types of mosquitoes and more diseases that the District has not seen yet.

Recent op-eds in the Washington Post and New York Times agree.

However, Wennersten adds that while mosquitoes will be a significant concern, the real issue will be the rising tides that will lead to not just more mosquitoes, but flooding, sewage in water, and disease.

“How much risk do we want to put up with as we move forward into the 21st century?” he asks.