Baltimore's Leaky Sewer System Delivers Traces of Amphetamine to Streams

The fractured, overflow-prone sewage system in Baltimore is causing chemicals from pharmaceuticals, personal care products and even illicit drugs to leak out to the city's waterways.

According to a report from the Baltimore Sun, traces of amphetamine, a drug used to treat ADHD, narcolepsy and obesity, as well as the recreational drug methamphetamine, were detected in the water samples taken from the Gwynns Falls watershed.

Traces of pharmaceutical and illegal drugs are not unusual in waters around the world. Most of the medications consumed by humans pass out of their body when they go to the bathroom. These chemicals are then flushed untreated through wastewater plants and are discharged into rivers and streams.

However, Baltimore Brew reported that the traces of compounds detected at Gwynns Falls most likely came from the city's leaking sewer system, which is in fact not new. In 2015, efforts to complete sewer repairs did not meet the deadline. Officials and federal regulators in Baltimore have agreed to allocate $1.2 billion to work on the repairs of their damaged sewer network for the next 15 years.

In a paper published in the journal Environmental Science and Technology, researchers discovered that the presence of amphetamine in streams could alter the ecological system of the wateway. Traces of the drug could influence the biofilm, seston and aquatic insect communities of the stream.

For the paper, the researchers set up four artificial streams with similar doses of amphetamine detected at six stream sites along the urban to rural gradient in Baltimore. The researchers observed a 45 percent reduction of biofilm chlorophyll a per ash-free dry mass and 85 percent decrease in biofilm gross primary production in artificial streams treated with amphetamine.

Furthermore, the amphetamine-treated faux streams have 24 percent greater seston ash-free dry mass, and 30 percent lower seston community respiration compared to control streams.

Midge larvae feeding on the biofilms of streams with amphetamine were observed to develop into flies quickly compared to the control streams. These might be good news for those animals feeding on the flies. However, researchers need further study fo prove that the faster development of flies is really productive for the stream ecology.