Arsenic                 package:NADA                 R Documentation

_D_i_s_s_o_l_v_e_d _a_r_s_e_n_i_c _c_o_n_c_e_n_t_r_a_t_i_o_n_s _i_n _g_r_o_u_n_d _w_a_t_e_r _o_f _U._S.

_D_e_s_c_r_i_p_t_i_o_n:

     This dataset is a random selection of dissolved arsenic analyses
     taken during the U.S. Geological Survey's National Water Quality
     Assessment program (NAWQA).

_U_s_a_g_e:

         data(Arsenic)

_F_o_r_m_a_t:

     A list containing 50 observations with items `As', `AsCen',
     `Aquifer'. `As' is a numeric vector of all arsenic observations
     (both censored and uncensored).  `AsCen' is a logical vector
     indicating where an element of `As' is censored (a less-than
     value).  `Aquifer' is a grouping factor of hypothetical hydrologic
     sources for the data.

_S_o_u_r_c_e:

     U.S. Geological Survey National Water Quality Assessment Data
     Warehouse

_R_e_f_e_r_e_n_c_e_s:

     The USGS NAWQA site at <URL: http://water.usgs.gov/nawqa>

