.icon {
    position: relative;
    top: 1px;
    display: inline-block;
    background: transparent url('https://www.dvrpc.org/webmaps/img/dataportal/index.png') no-repeat;
    height: 18px;
    width: 18px;
    content: ' ';
}
.icon-fbD {
    background-position: -53px 0;
}
.icon-instagramD {
    background-position: -106px 0;
}
.icon-twitterD {
    background-position: -142px 0;
}