public void setSCADASites(ArrayList<SCADASite> sites) {
    // remove all previous markers
    Marker[] markers = googleMap.getMarkers();
    for (Marker marker : markers) {
      googleMap.removeMarker(marker);
    }

    // then add the new ones
    markers = new Marker[sites.size()];
    for (int i = 0; i < markers.length; i++) {
      SCADASite site = sites.get(i);

      String color;

      crit = false;
      warn = false;

      if (site.getAlarm()) {
        color = "red";
        crit = true;
        playSound();
        firstAlarm = false;
      } else if (site.getWarning()) {
        color = "orange";
        warn = true;
        firstAlarm = true;
      } else {
        color = "green";
        firstAlarm = true;
      }

      Marker marker = new Marker(googleMap, site.getLat(), site.getLon(), color);
      googleMap.addMarker(marker);
    }

    repaint();
  }