Thank You to Biosolids Practitioners This is the last library of 2016 and it arrives in that frantic period between Thanksgiving and New Years. This is not the time to read about interactions between biochar and biosolids or the response of rhizobia to Zn in biosolids. That can wait until the New Year and the February library.

This is the time to give thanks. And this library is my way of giving thanks to you and all that you do.

As people who work with wastewater, in a place where wastewater treatment is a long ago mandated legal requirement, you likely lose track of the value of what you do in the day to day flood of spreadsheets, testing, permits and so on. The day-today tasks can make you forget the bigger picture and the bigger benefits. Trucking expenses and the cost of polymer are the debits you see on those spreadsheets where traditionally there are no columns that help you quantify the returns from what you do. This library gives some examples of those returns.

The library starts with an article that summarizes the value of wastewater treatment itself. The article is a compendium of facts and texts from different sources. It starts with a discussion of how we have not put appropriate dollar values on many of the natural resources that are so critical for our survival. This includes clean water. It talks about the fundamental right of access to clean water. There is a direct link between appropriate wastewater treatment and access to clean water. World maps showing access to each are provided. While strides have been made for access to water, satisfactory wastewater treatment is lagging. As of 2011, 768 million people did not have access to improved drinking water, and 2.5 billion had no access to improved sanitation. Work in 2006 suggested that the deficit in investment in water and sanitation is $170 billion dollars, or 2.6% of the GDP of all developing countries.

So, what would the return be if that money was spent on drinking water and sanitation? According to the UN, every $1 spent on water and sanitation returns $8 in averted costs, and the World Health Organization estimated a $3 - $34 return.

Where do these returns come from? The article includes a bulleted list of reduced illness and more productive time. The productive time is significant -- a gain of 3.2 billion working days as a result of avoided diarrhea and an additional 20 billion days for reduced time spent trying to access clean water. Think about what your spreadsheets would look like if you added in numbers like that! And you could make such a calculation, but we have had clean water and excellent sanitation for so long a time that we forget what a gift it is.

From there we move onto the benefits of biosolids and their impact on soils. Here the focus is not on parts per trillion concentrations of headache medicine but on the fact that we need healthy soils to survive. This is the fact that is often lost when we focus on the pharmaceuticals.

The second article is by Rattan Lal, a world-recognized leader in soil science and soil carbon sequestration. Lal makes the connection between soil carbon sequestration, soil health and food security. When you add carbon to soils, you improve soil health, and that in turn is a way to provide for enhanced food security. His tools for improving soil health include no-till or reduced-till agriculture and biosolids. Yes! on the 2nd page of the article Lal specifically notes that biosolids are a tool to both add carbon and nutrients to the soil.

While Lal persuasively argues that improving soil health through enhanced carbon sequestration is critical to making sure we have food to eat and water to drink, he does not put a dollar figure on this. Here we go to the third article that summarizes a recent news release about General Mills and the Nature Conservancy. Both are now focusing on soil health (same as Lal), but here they add a price to this -- $50 billion dollars. General Mills is trying to reduce food waste and has urged our current president-elect to respect the science that climate change is real. They firm has also set soil health as a company priority. General Mills has a road map that provides 10 steps to soil health. If these were adopted on 50% of US cropland by 2025, farmers would see $1.2 billion in annual economic gains, and society would enjoy an additional $7.4 billion in water and climate benefits. Now biosolids and composts are not mentioned in this road map, but I can promise you that those figures would go up if they were added.

We know the value of sanitation for public health, and we know the value of biosolids for soils and growing foods. Now, let’s take this the next step, as many municipalities are doing, and look at the value of biosolids for improving soils other than traditional cropland. Let’s say that biosolids and composts are used to restore disturbed lands both inside cities whether the uses are for tree plantings, green storm water systems, parks or urban agriculture. The last two articles look at the impact of natural or green areas on public health using two different lenses. The first article, published in 2006 did a broad survey on the impact of green areas on general health. The authors found that the percentage of green space within an urban area was significantly related to perceptions of general health, with the impact most pronounced for lower socio-economic groups, the elderly, young and those with secondary education. This is something that you can take to your city managers.

The library closes with a new article that looks at the relationship between urban blight and firearm violence. The authors found a significant relationship between greening of these lots and a reduction in violence associated with guns. The taxpayer and societal returns associated with urban greening were $5 and $79 for every dollar spent. What a surprise if, as is likely, you had only looked at urban uses of biosolids to reduce trucking costs. Add in violence reduction, and the benefits are extraordinary!

For this holiday season, let me give thanks to what you do every day. I hope that this library provides you with a fresh perspective on the critical nature of this work and its true value. What a better world it would be if, with every flush, our citizens acknowledge your good works and their own contribution.

Sally Brown, University of Washington