Geochemical Assessment of Abandoned Mine Discharges on Wiconisco Creek, Schuylkill and Dauphin Counties, Pennsylvania
Start Date
10-11-2017 8:00 PM
End Date
10-11-2017 9:59 PM
Description
I investigated the impact of the three mine drainages on water quality in Wiconisco Creek, a 43 mile tributary of the Susquehanna River. Located in lower Schuylkill and upper Dauphin Counties, Wiconisco Creek has historically been called “black creek” by locals due to excessive coal sludge in the stream. Abandoned mine drainage (AMD) also impacts water quality in the stream. All three AMD inputs have treatment systems (two passive and one active) in place. Each system is different and specifically designed for that particular AMD. Discharge from the Porter Tunnel is low pH and alkalinity and high in metals (especially iron and aluminum) requiring treatment with both limestone and settling ponds. Discharge from Big Lick Tunnel is high in iron and low in dissolved oxygen requiring only a serious of vertical drops to aerate the water and precipitate iron. Discharge from Short Mountain Mine is also high in metals and low in dissolved oxygen requiring a series of 3 settling ponds. For each of these drainages, samples were collected both above and below the treatment systems and above and below the confluences of the treated water with the Wiconisco Creek. Conductivity, pH, dissolved oxygen, and temperature were measured in situ using a Hach™ HD40 meter with probes. Large volume samples were collected, transported to the lab, and filtered. Alkalinity and acidity were immediately determined in the lab. Additional chemical analyses were later performed on preserved samples using ion chromatography (IC) for simple cations and anions and inductively coupled plasma – optical emission spectroscopy (ICP-OES) for 11 selected metals. Porter Tunnel had the lowest pH (3.62) and lowest alkalinity (0 mg/L as CaCO3) compared to those of Big Lick (7.04 and 100 mg/L as CaCO3) and Short Mountain Mine (6.58 and 21.0 mg/L as CaCO3). Conductivity was highest in Porter Tunnel AMD (843 µS/cm) compared to that from Big Lick (283 µS/cm) or Short Mountain Mine (174.9 µS/cm). Results of ion and metal analyses indicate that it is not due to dissolved iron, aluminum and manganese as originally predicted, but due to high levels of sodium, chloride, magnesium, and calcium, indicative of road salt contamination.
Keywords
Wiconisco Creek, Abandon Mine Drainage, mine water, mine drainage
Type
Poster
Session
Poster session
Language
eng
Geochemical Assessment of Abandoned Mine Discharges on Wiconisco Creek, Schuylkill and Dauphin Counties, Pennsylvania
Elaine Langone Center, Terrace Room
I investigated the impact of the three mine drainages on water quality in Wiconisco Creek, a 43 mile tributary of the Susquehanna River. Located in lower Schuylkill and upper Dauphin Counties, Wiconisco Creek has historically been called “black creek” by locals due to excessive coal sludge in the stream. Abandoned mine drainage (AMD) also impacts water quality in the stream. All three AMD inputs have treatment systems (two passive and one active) in place. Each system is different and specifically designed for that particular AMD. Discharge from the Porter Tunnel is low pH and alkalinity and high in metals (especially iron and aluminum) requiring treatment with both limestone and settling ponds. Discharge from Big Lick Tunnel is high in iron and low in dissolved oxygen requiring only a serious of vertical drops to aerate the water and precipitate iron. Discharge from Short Mountain Mine is also high in metals and low in dissolved oxygen requiring a series of 3 settling ponds. For each of these drainages, samples were collected both above and below the treatment systems and above and below the confluences of the treated water with the Wiconisco Creek. Conductivity, pH, dissolved oxygen, and temperature were measured in situ using a Hach™ HD40 meter with probes. Large volume samples were collected, transported to the lab, and filtered. Alkalinity and acidity were immediately determined in the lab. Additional chemical analyses were later performed on preserved samples using ion chromatography (IC) for simple cations and anions and inductively coupled plasma – optical emission spectroscopy (ICP-OES) for 11 selected metals. Porter Tunnel had the lowest pH (3.62) and lowest alkalinity (0 mg/L as CaCO3) compared to those of Big Lick (7.04 and 100 mg/L as CaCO3) and Short Mountain Mine (6.58 and 21.0 mg/L as CaCO3). Conductivity was highest in Porter Tunnel AMD (843 µS/cm) compared to that from Big Lick (283 µS/cm) or Short Mountain Mine (174.9 µS/cm). Results of ion and metal analyses indicate that it is not due to dissolved iron, aluminum and manganese as originally predicted, but due to high levels of sodium, chloride, magnesium, and calcium, indicative of road salt contamination.