\documentclass[10pt]{article}

\usepackage[lmargin=0.3in, rmargin=0.3in, tmargin=0.9in, bmargin=0.9in, paperwidth=10.0in, paperheight=7.5in]{geometry}
\usepackage{multicol}
\usepackage{graphicx}
\usepackage{fancyhdr}

\pagestyle{fancy}

\begin{document}
    \lhead{\bfseries{\Large{$title$ - $population$ samples}}}
    \rhead{}
    \chead{}

    \begin{center}
        \includegraphics[height=125mm, type=pdf, ext=.pdf, read=.pdf]{$plotprefix$}
    \end{center}

    $caption$

    \lfoot{}
    \cfoot{}
    \rfoot{\small{1,000 Genomes Automated Data Processing Report ($timestamp$)}}
\end{document}