Usoda skrb vzbujajočih onesnaževal v jezerih, nastalih v vrtačah, Florida, ZDA

Zakrasele karbonatne platforme, kot je Florida, zaznamujejo hitra stopnja infiltracije, visoka prepustnost podlage in neposredna povezava z vodonosniki prek številnih vrtač. Kombinacija teh fizikalnih lastnosti prispeva k visoki občutljivosti podtalnice in vodonosnikov na kontaminacijo s skrb vzbujajočimi sintetičnimi kemikalijami. Uporaba greznic spodbuja vnos teh onesnaževal v okolje. Da bi proučili vpliv kemikalij na kraško pokrajino, so bili vzorci vode, sedimenta in vegetacije odvzeti v jezeru, nastalem v vrtači in obdanem s stanovanji, ki so opremljena z greznicami. Glavno vprašanje tega raziskovalnega projekta je, kaj se dogaja z onesnaževali iz grezničnih odplak v vodnem zajetju vrtače. Za analizo vzorcev je bila izvedena masna spektrometrija s tekočinsko kromatografijo. Ugotovljeno je bilo, da je sorazmerna količina kemikalij odvisna od 1) hidrofobnosti in polarnosti spojine, 2) mesta vzorčenja, 3) topografskega gradienta in 4) za vegetacijo, povezanosti vrste vzorca s sedimentom. Hidrogeološke študije so pokazale, da so vrtače na tem območju povezane z vodonosnikom, ki je pod njimi. Posledično skrb vzbujajoča onesnaževala predstavljajo tveganje za onesnaženje podtalnice. Ta študija je prikaz razmer v sušni sezoni Floride, to je najverjetneje obdobje z najmanjšo kontaminacijo. Vzorčenje bi bilo treba opraviti v tudi deževnem obdobju, ko izpiranje onesnaževal iz greznic lahko poveča koncentracije onesnaževal, tako v jezeru kot v vodonosnikih, kar je posebno problematično zaradi uporabnosti vode iz vodnjaka v prehranske namene. Čeprav je bila študija izvedena na Floridi, verjamemo, da so naše ugotovitve in priporočila splošno uporabni, saj se greznice uporabljajo v številnih kraških predelih sveta.Highly karstified carbonate platforms such as Florida are characterized by rapid infiltration rates, highly permeable bedrock and the direct connection to the below aquifer through the high density of sinkholes. This combination of physical features makes the groundwater and aquifers highly vulnerable to contamination from synthetic chemicals commonly referred to as contaminants of emerging concern (CECs). The use of septic tanks, otherwise referred to as onsite water treatment systems (OWTS), promotes the introduction of CECs into the environment. In order to study the impacts of CECs from OWTS on a karst landscape, water, sediment, and vegetation samples were collected in a sinkhole lake surrounded by residential housing using this waste disposal method. The main question of this research project is what is the fate of CECs from OWTSs effluent within the catchment of a sinkhole lake? Liquid chromatograph mass spectrometry was used to analyze the samples for the presence of CECs. It was found that the relative quantity of CECs in the individual constituents is dependent upon 1) the hydrophobicity and polarity of the individual compound, 2) the specific sampling site, 3) the topography gradient, and 4) for vegetation, the connectedness of the sample type to the sediment. Hydrogeological studies have found that the sinkholes of the area are all connected to the below aquifer. Consequently, these CECs pose a risk of the contamination of the groundwater. This study is a temporal snapshot, that being the dry season of Florida which is most likely the time of lowest CEC contamination. It is imperative that sampling extend into the wet season when flushing of CECs from the OWTS may increase their concentrations in both the lake but also the aquifers especially since residents use well water as their source of potable water. While this study is based in Florida, we strongly suspect that our findings and recommendations are applicable more generally as OWTS are used throughout the many karst regions of the world

Sinkhole Lake Infiltration of Contaminants of Emerging Concern from Onsite Water Treatment Systems

The advancement in synthetic chemicals commonly referred to as contaminants of emerging concern (CECs) and their application has led to an increase in environmental pollution. The use of septic tanks otherwise referred to as onsite water treatment systems (OWTS), promotes the introduction of CECs into the environment while allowing little in the way of remediation. In order to study the impacts of CECs from OWTS as they infiltrate the environment and the aquifer system, water, sediment, and vegetation samples were collected around a sinkhole lake surrounded by residential housing using OWTSs. The main question of this research project is what is the fate of CECs from OWTSs effluent within the catchment of a sinkhole lake? Liquid chromatograph mass spectrometry was used to analyze the samples for the presence of CECs. It was found that the relative quantity of CECs in the individual constituents is dependent upon 1) the hydrophobicity and polarity of the individual compound, 2) the specific sampling site, 3) the topography gradient, and 4) for vegetation the connectedness of the sample type to the sediment. The implications derived from this study can be applied in environmental engineering, urban and suburban planning, environmental monitoring, and should be considered when residents use well water as their source of potable water