Although aesthetically displeasing, tannins do not pose a health issue. However, if tannins are found in the water, it can indicate that your water is significantly influenced by surface water. Put simply, this means that if tannins can travel easily from surface water to your groundwater source, pathogens can easily travel through as well.
JPG is a file extension for a lossy graphics file. The JPEG file extension is used interchangeably with JPG. JPEG stands for Joint Photographic Experts Group who created the standard. JPG files have 2 sub-formats, JPG/Exif (often used in digital cameras and photographic equipment), and JPG/JFIF (often used on the World Wide Web).
JPEG-Joint Photographic Experts Group. (.JPG file extension, pronounced Jay Peg). This is the right format for those photo images which must be very small files, for example, for web sites or for email. JPG is often used on digital camera memory cards, but RAW or TIF format may be offered too, to avoid it. The JPG file is wonderfully small, often compressed to perhaps only 1/10 of the size of the original data, which is a good thing when modems are involved.