Your silver was not created by the mine. It was likely created hundreds of thousands of years or more before modern humans even existed, possibly as part of a hydrothermal depositional sequence of related elements and compounds. Depending on your local geology this could have occurred as super-heated, mineral-laden fluids rose up under natural pressure through cracks in the earth caused by tectonic activity. As those fluids cooled they precipitated out into various mineral suites within those cracks, which we call veins, some of which included silver and/or silver compounds. Gold is often also part of that particular sequence.
It's possible that the silver in your backyard has been there since before mankind ever evolved as a viable species. Mining is the process by which that element is concentrated to a useful level for our needs and purposes. Once our purpose is served, that silver will be returned to the earth's structure from whence it originally came, to again lie quietly while awaiting its future fate.
The concept of waste is a human economic one. It's not a natural process. Waste is the economic process whereby the cost to concentrate (mine) a resource exceeds the value derived from the subsequent use of that concentrate to generate value. If you pay $100 to concentrate an ounce of silver, but can subsequently only generate $50 in value from use of that concentrated silver, you have "wasted" $50 of your original value. That may be an important distinction to you, but it's not a distinction at all to Nature.
But the silver atoms themselves are unaffected. Whether they exist in their originally precipitated deposit in the earth, or are hanging on your wall as a photographic print, or have been re-deposited back into the earth in your leech field as harmless silver sulfide, or were more likely pumped from your septic tank and transported and re-deposited back into the earth somewhere else, makes little difference. They have not been lost. They have not been wasted. They have not been transmuted into another element. They still exist, and could again be recovered from leech fields if the future economics to do so made sense.