DOI: 10.7291/d11592
title: Cordillera Huayhuash Water Quality 2010-2011

description: The Cordillera Huayhuash is the second highest mountain range in the
 Peruvian Andes and is important for tourism, mining, and local
 livelihoods. These three economic activities all share an interest in the
 water quality of the over 50 lakes and associated drainages that exist in
 the region. Water quality monitoring can help ease tensions between
 interests from these distinct economic sectors. This dataset reports on
 two rounds of water quality sampling and testing performed at 56
 identified monitoring stations in 2010 and 2011. Several additional spot
 samples were taken in both years. At each monitoring station field
 measures such as temperature, pH, and conductivity were taken and samples
 were collected for laboratory analysis of elemental concentrations (metals
 and others) and field analysis of biological contamination (enterococcus).
 The results show contamination from mining activities, from tourism
 activities and from natural sources. The data is in a comma separated
 value (CSV) format with two flat files: "Pruebas.csv" contains
 the measurements of all parameters for each sample;
 "Estaciones.csv" contains a list of monitoring stations with
 geographic coordinates; "README.csv" contains the data
 dictionaries and other metadata (description) for both of the flat files.
description: Two rounds of water quality sampling and testing were performed
 in 2010 and 2011 at 56 identified monitoring stations in the Cordillera
 Huayhuash, Peru. Several additional spot samples were taken in both 2010
 and 2011. The selection of monitoring stations was guided by several
 criteria. At least two monitoring stations were identified per watershed;
 one at the headwaters (slightly downstream from a trekking camp if
 possible) and one near the confluence with the neighboring watershed. One
 monitoring station was identified at the source of drinking water for each
 community. Additional monitoring stations were identified as potential
 sites of contamination from mining activities. All of the monitoring
 station identification met Peruvian Ministry of Energy and Mines published
 protocols (MEM, 1994. Protocolo de Monitoreo de Calidad de Aguas. Lima,
 Peru: Ministerio de Energia y Minas). Samples were collected during April
 and May across two consecutive years; 51 stations in 2010 and 36 stations
 in 2011 of which 32 stations were used both years (see stations.csv).
 Field measurements were made for temperature, pH, conductivity, salinity,
 total dissolved solids, and dissolved oxygen with two distinct field
 instruments (the Oakton Instruments PCSTester35 multi-parameter tester and
 the Oakton Instruments ExStik® DO600 oxygen meter respectively). The
 American Public Health Association (APHA) methods 9222 and 9230 (APHA,
 2005. Standard methods for the examination of water and waste water, 21st
 edition. American Public Health Association, American Water Works
 Association & Water Environment Federation: Baltimore, Port City
 Press) were followed for the analysis of fecal coliforms (Enterococcus
 spp.) in the field. Each measured sample was filtered with a 0.45 micron
 gridded filter. Each filter was then incubated at approximately 44.5° C
 for twenty four hours on Agar specially formulated for Enterococcus
 growth. The number of colonies that appeared was counted and a most
 probable number (MPN) was calculated using the number of colonies observed
 and the amount of water originally filtered. In 2010 split filtered (0.45
 micron) and unfiltered samples were collected for heavy metal analysis at
 each monitoring station and in 2011 only unfiltered samples were
 collected. Across both years ½ liter was used as the sample volume. The
 collection bottles were provided by the laboratory and were guaranteed to
 be clean (according to EPA protocols detailed below). The collection of
 samples in the field followed the EPA protocols published in each method
 detailed below. In 2010 the unfiltered sample was analyzed for dissolved
 mercury (Hg) concentrations in a laboratory in Lima (EnviroLab S.A.C)
 using EPA method 1631 (Cold Vapor Atomic Fluorescence Spectrometry) (EPA,
 2002. Method 1631, Revision E: Mercury in Water by Oxidation, Purge and
 Trap, and Cold Vapor Atomic Fluorescence Spectrometry. Baltimore: United
 States Environmental Protection Agency). The Mercury measurement was not
 repeated the second year as no sample from 2010 yielded a positive result
 and no new sources of mercury were identified. In 2010 the unfiltered
 sample was analyzed for a full run of elemental concentrations (As, Ba,
 Be, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, Zn, Ag, B, Bi, Ca, Fe,
 K, Li, Mg, Na, P, Si, Sn, Sr, and Ti) with the EPA 200.8 method
 (inductively coupled plasma mass spectrometry) (EPA, 1994. Method 200.8
 Determination of trace elements in waters and wastes by inductively
 coupled plasma mass spectrometry. Cincinnati: United States Environmental
 Protection Agency). In 2011 the elemental analysis was narrowed to
 aluminum (Al), arsenic (As), cadmium (Cd), copper (Cu), manganese (Mn),
 nickel (Ni), lead (Pb), and zinc (Zn) based on the results from
 2010.