{"id":3650,"date":"2019-08-28T16:00:51","date_gmt":"2019-08-28T20:00:51","guid":{"rendered":"https:\/\/www.grecoandhaines.com\/?p=3650"},"modified":"2019-09-04T11:22:44","modified_gmt":"2019-09-04T15:22:44","slug":"groundwater-vs-surface-water","status":"publish","type":"post","link":"https:\/\/www.grecoandhaines.com\/groundwater-vs-surface-water\/","title":{"rendered":"The Difference Between Surface Water and Groundwater"},"content":{"rendered":"

When we think of freshwater, we tend to think of surface waters such as rivers, lakes, marshes, swamps, ponds, and other wetlands. It makes sense that this is the most familiar sort of water (along with, of course, the vast saltwater of the ocean), as it\u2019s the kind we see regularly. However, it\u2019s only a small portion of the Earth\u2019s freshwater, the bulk of which exists out of sight and below the surface. This underground water supply is commonly known as\u00a0groundwater.<\/p>\n

Let\u2019s take a look at the basic differences between groundwater and surface water, and how Greco & Haines can help you improve the quality of your home\u2019s water supply.<\/p>\n

Groundwater vs. Surface Water<\/h2>\n

Surface water includes the freshwater that is channeled into stream systems, lakes, and wetlands on land. Groundwater, on the other hand, is contained in subterranean aquifers within the rock layers below the\u00a0water table \u2013\u00a0the underground boundary that divides the saturated and unsaturated levels of the ground. Groundwater derives primarily from rainfall and snowmelt that infiltrates through the soil and into the bedrock, where, driven by gravity, it collects between particles, fractures, and cavities inside rock layers.<\/p>\n

The majority of the Earth\u2019s groundwater lies within a half-mile of the surface. When it hits an impermeable subterranean layer \u2013 such as massive, nonporous rock or clay \u2013 the groundwater pools and may flow laterally along it.<\/p>\n

While groundwater might remain ensconced in aquifers for thousands of years, it can also naturally appear at the surface in the form of springs, seeps, and groundwater-fed lakes. This is due to its movement within sedimentary strata or along impervious geologic layers.<\/p>\n

While surface waters are widely used all over the world for human needs, groundwater aquifers supply most of the drinking water in the United States. When you use a well system, you are tapping the groundwater supply on your property.<\/p>\n

Surface Water vs. Groundwater Quality<\/h2>\n

Through runoff, air fallout, and other sources, surface water can contain significant amounts of contaminants such as chemical pollutants. And because groundwater is connected to surface water systems through soil percolation and seepage, it is also susceptible to contamination. However, the rock and sediment layers below the water table act as natural filters. Therefore, groundwater generally contains fewer contaminants than surface water and requires less treatment.<\/p>\n

Minerals in Water \u2013 Groundwater & Hardness<\/h2>\n

While groundwater typically contains fewer contaminants than your average surface water, it does tend to have higher mineral content due to the dissolving action of water. In fact, water is often referred to as the \u201cuniversal solvent\u201d because it dissolves more substances than any other liquid. Mineral content is the measure by which we classify water as \u201chard\u201d or \u201csoft.\u201d Hard water contains large amounts of certain ions (primarily calcium and magnesium) while soft water has a lower mineral concentration.<\/p>\n

We commonly quantify hardness by measuring the concentration of calcium and magnesium in water and then converting it to the equivalent amount of calcium carbonate, expressing the figure in milligrams per liter (mg\/L) of water. The\u00a0U.S. Geological Survey<\/a> divides water into four different categories based on mineral content, including:<\/p>\n