The Use of Multiple Tracers to Evaluate the Impact of Sewered and Non‐Sewered Development on Coastal Water Quality in a Rural Area of Florida

Abstract

When onsite wastewater treatment and disposal systems (OSTDS) are not sited appropriately or installed properly, wastewater constituents can be a source of adverse environmental impacts to soil and groundwater, which can lead to potential public health risks. A paired monitoring design developed to compare water quality in sewered and non‐sewered areas is presented here. It is suggested as a possible monitoring scheme for assessing the impact of sewer installation projects. As such, two sets of single‐family, rural residential Florida neighborhoods were evaluated over a two‐year period to gain insight into the effects of small‐community use of OSTDS on coastal water quality. One set of two neighborhoods were connected to the sanitary sewer network and the other set of two were served exclusively by OSTDS. Water quality sampling was conducted at the paired sites during seasonal high water table (SHWT) and seasonal low water table (SLWT) events. Measured surface water quality during the SHWT showed indications of environmental impacts from OSTDS in terms of nutrients, microbial pathogen indicators, and other water quality measures, such as turbidity and conductivity. However, during the SLWT events, no obvious impacts attributable to OSTDS were detected. The water quality results indicate that OSTDS impacts may be measureable in rural areas. Other factors, such as microbial indicator survival and regrowth potential, may confound the understanding of water quality impacts of sewer projects. For example, the microbial indicators Escherichia coli and enterococci were found to persist over time and therefore did not always represent true comparisons of OSTDS and sewered areas between seasons. The timeframe for evaluating the effects of sewer projects may be longer than anticipated because of this survival and regrowth phenomenon.

Non-Point Sources (Septic Tanks) of Surface Water Nutrient Pollution: A Review and a Study of Taylor Creek, Okeechobee County, Florida

“…South Florida has been and still is experiencing nutrient (N, P) excesses in the surface waters and sediments of Lake Okeechobee (Havens, 1995;Walker and Havens, 1995;Havens and East, 1997;Recheigl, 1997;FDEP, 2001FDEP, , 2018FDEP, , 2019Fisher et al, 2001;Havens et al, 2005;Engstrom et al, 2006;Byrne and Wood, 2011;Pollman and James, 2011;US-ACE, 2016;Zhou and Struve, 2016), coastal estuaries (Lapointe et al, 1990(Lapointe et al, , 2012(Lapointe et al, , 2015Lapointe and Clark, 1992;Lapointe and Krupa, 1995;Pant and Reddy, 2001;Phlips et al, 2002;Liu et al, 2009;Tarnowski, 2014;Duersch and Louda, 2017;), and the Greater Everglades (Childers et al, 2003;Bruland et al, 2007;Louda et al, 2015;Reddy et al, 2011). Sources include sewerage, notably septic systems (aka OSTDS, Onsite Sewerage Treatment and Disposal Systems: Badruzzaman et al, 2012;FDOH, 2013;Meeroff et al, 2014;Lapointe et al, 2017), agricultural operations (Boggess et al, 1993;Stuck et al, 2001;Duersch et al, 2017Duersch et al, , 2020Duersch et al, , 2021 and a growing equestrian industry (Louda et al, 2021).…”

“…A wide variety of tracing methods have evolved to assess sources, directions, and quantities of sewerage pollution (Meeroff and Morin, 2005;Meeroff et al, 2014). "Transport Modelling" in which chloride (Cl -), electrical conductivity, numerous groups of bacteria and viruses (biological tracing) has been reported (Alhajajar et al, 1988;Ahmed et al, 2006).…”

Phosphorus Non-Point Pollution from Equestrian Wastes and the Need for Recycling

“…South Florida has been and still is experiencing nutrient (N, P) excesses in surface waters and sediments in Lake Okeechobee (Fisher et al, 2005;Havens, 1995;Havens and East, 1997;Havens and Thomas, 2005;Pollman and Thomas, 2011;), coastal estuaries (Duersch and Louda, 2017;Liu et al, 2009;Pant and Reddy, 2001;Phlips et al, 2002 ) and the Greater Everglades (Bruland et al, 2007;Childers et al, 2003;Coralles et al, 2014;Louda et al,2015;Reddy et al, 2011). Sources include sewerage, notably septic systems (aka OSTDS, Onsite Sewerage Treatment and Disposal Systems: Badruzzaman et al, 2012;FDOH, 2013;Lapointe et al, 2017;Meeroff et al, 2014), agricultural operations (Boggess et al, 1997;Duersch et al, 2020;Entry and Gottlieb, 2014;Stuck et al, 2001) and a growing equestrian industry (Cintron and Louda, 2007;Louda et al, 2019;Osetek and Louda, 2004).…”

Microbial Water Quality Conditions Associated with Livestock Grazing, Recreation, and Rural Residences in Mixed-Use Landscapes

“…The identification and mitigation of microbial pollutant sources in mixed-use rural watersheds is an issue spanning the globe (e.g., New Zealand [20], United Kingdom [21], Canada [22], China [23], and the United States [24]). Livestock agriculture (e.g., [25][26][27]), septic systems, and wastewater treatment systems (e.g., [28][29][30]) are all documented as potential anthropogenic sources of microbial pollutants in rural watersheds. Studies also document the potential for microbial pollutant contributions from environmental sources such as wildlife (e.g., [31][32][33]), soil, and streambed sediments (e.g., [24,[34][35][36][37]).…”