Water Scarcity
Today many topics of discussion and concerns among the environmental crowd as well as general population are water quality, air quality and climate related. In many cases, conditions surrounding these topics are interrelated. While air quality and climatic changes have been in the forefront for as long as I can remember, water as it relates to its most suitable and beneficial end use is a more recent topic. While the earth is about 70 percent covered by water, not all of it is available and not all of it is usable for the desired purpose without comparatively high treatment costs. In fact, only about 3 percent is fresh water of which about 60percent is locked up in glaciers and ice caps. This leaves about 1 percent of all the fresh water on earth (about 3.25million trillion gallons) available to meet the needs of everyone here. Keep in mind, this 1 percent also contains the polluted fresh water volumes as well.
Considering an ever growing human population, climate change and other lesser factors, finding adequate drinking water supplies is becoming increasingly more difficult. This issue as it relates to population growth becomes more tenuous as the areas with the greatest number inhabitants become more centralized. To that end, we need to become better at strategic use of source waters to their highest practical end use. For instance, if reclaimed water is available for golf course, general agriculture, industrial processes, then use of a high quality water source that could otherwise be used for drinking water would be inappropriate.
Protection of Water Sources
There are several areas of concern with regard to protection and preservation of existing water sources. Some of the major areas of concern are river water quality and volume, salt water intrusion in coastal plains and oil/gas hydraulic fracturing (fracking). While each has played a role in raising concerns regarding sustainable water for future generations, those surrounding the rivers and coastal plains have been more gradual. Oil/gas on the other hand, has been “front and center” in areas where the preferred method of extraction is fracking. Here lies the concern, mostly with the possibility of contamination of entire aquifers by breaches in borehole casings or fracturing of underground strata. In one Bakersfield, CA case, whereby 3billion gallons of fracking wastewater was injected into clean aquifers. This potential contamination can take the form of endogenous compounds and/or compounds used to aid in fracking process. Before institution of the Clean Water Act and the NPDES program that followed, river water quality was the item of biggest concern, as the water quality of many waterways had degraded to the degree that they could no longer be used for their intended purposes (recreation, drinking water, natural habitat). More recently, the focus has shifted from quality to quantity due to increased water demand as a result of steadily increasing human population and irrigation. This in conjunction with less favorable climatic conditions that has affected both source water volumes as well as demand for irrigation for both crops, homeowners and all others in between.
Bio-Solids Beneficial Reuse
Bio-solids are a more recent description for what has historically been described as sludge. In the past bio-solids were viewed as a byproduct of the biological wastewater treatment process. This is a process containing a variety of concentrated largely endogenous microbial populations under more ideal environmental conditions than would naturally occurring to degrade waste stream pollutants to acceptable levels.
Recent EPA regulations have made the need to manage bio-solids in a more beneficial manner a greater necessity. In the past dumping into the ocean and landfilling were both fairly common practices but have since been displaced due to mandates for more beneficial uses of process residuals or bio-solids. The ultimate goal of the EPA in this case is make bio-solids more of an asset than a liability. Many of the past practices resulted in some degree of environmental pollution and/or needless use of landfill volume. In a time where the general consensus is that we should be conserving and recycling as much as possible, further treatment of bio-solids to make them more amenable to improved end applications “falls in line” and makes sense. After all, not needlessly using the landfill space for bio-solids disposal in favor of the more appropriate refractory type pollutants both extends the landfill useful life as well as provides a greater and more natural end use.
Beneficial end uses of non-agricultural bio-solids can include use as a fertilizer (Class A product) with no more restrictions than would be required of a commercial fertilizer. It can also include a lesser grade fertilizer type product (Class B product) with more restrictive land use requirements but still very useful as a soil amendment product. It should be noted that land application requirements for agricultural bio-solids are generally must less restrictive than that for the non-agricultural variety.
Summation
In general, we must learn to manage our resources better so that adequate usable volumes of water are available for future generations. Additionally, better bio-solids “disposal” practices will help reduce the volume of landfills that could otherwise be occupied by waste material that does not have as many alternative disposal routes.