ORIGINAL ARTICLE An environmental investigation of the mineralogical, geotechnical, hydrogeologic and botanical properties of subsurface flow constructed wetlands in Akumal Mexico Sheela Varma Sinha • Erin P. Argyilan • Mark P. S. Krekeler Received: 7 August 2013 / Accepted: 1 August 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract Akumal is one of the few locations where subsurface flow constructed wetland systems can be com- pared directly without major differences in environmental setting. These systems in Akumal have highly variable geotechnical properties and performance and most systems are not well functioning. A basic water quality survey indicates SFCW effluent in no case meets UNEP or USEPA guidelines for ammonia or phosphate for sensitive waters. Systems are undersized and many are planted with less than optimal vegetation. Aggregate is generally too coarse and pores are commonly occluded with organic matter. The mineralogy of the locally sourced aggregate used in the systems is dominated by calcite, aragonite, quartz, boehmite and chlorite and is generally beneficial for improving the water quality of the systems; however, dis- solution is observed and is of some concern. Major sys- tematic retrofit efforts to improve these systems are warranted and should focus on better vegetation choices, use of locally sourced smaller and less soluble aggregate, exclusive use of the local limestone source containing boehmite, more frequent exchange of the aggregate, and an increase of overall cell size. The systems in Akumal are a classic example of a technological solution to an environ- mental problem caused by human development that has outpaced the designed capacity for wastewater treatment. This investigation serves as a baseline for numerous future interdisciplinary investigations and outlines challenges facing coastal communities attempting to use subsurface flow constructed wetlands. Keywords Constructed wetlands Á Aggregate Á Shannon diversity index Á Wastewater treatment Á Yucata ´n Mexico Introduction The Yucata ´n peninsula in Mexico is one of the world’s major tourism destinations and is an exemplar of the globalization of the tourism industry. Murray (2007) reported that 6 million tourists entered the region in 2006, up from an estimated three million tourists in 2003. The economic development in this region has been accompa- nied by extensive social and environmental impacts (e.g. Murray 2007; Torres and Momsen 2005). The issue of wastewater is central to many environmental problems given its negative effects on human and environmental health including the potential degradation of the Meso- American reef (Pacheco and Cabrera 1997; Aguilar and Garcia De Fuentes 2007; Krekeler et al. 2007; WHO 2007). Constructed wetlands are engineered ecosystems which involve the use of hydrologic, biologic and mineralogical processes to reduce wastewater volume and decrease or eliminate the polluting components of wastewater. These systems have a variety of designs with horizontal surface Electronic supplementary material The online version of this article (doi:10.1007/s12665-014-3577-y) contains supplementary material, which is available to authorized users. S. Varma Sinha Department of Environmental Science and Policy, George Mason University, Fairfax, VA 22030, USA e-mail: srv.sheela@gmail.com E. P. Argyilan Department of Geosciences, Indiana University Northwest, Gary, IN 46408, USA e-mail: eargyila@iun.edu M. P. S. Krekeler (&) Department of Geology and Environmental Earth Science, Miami University-Hamilton, Hamilton, OH 45011, USA e-mail: krekelmp@miamioh.edu 123 Environ Earth Sci DOI 10.1007/s12665-014-3577-y