Paying the Piper

The amount of sediment that is allowed to runoff into the Chesapeake Bay is forty times by weight the amount of nitrogen and 500 times the amount of phosphorus allowed. Now that the Conowingo Dam is silted to the point that scoured sediment is washing through, it will become harder to meet the decreasing sediment limits without dredging. However, the real problem is phosphorus since the sediment contains much more than a 1:500 ratio. Who will pay for the dredging?

Exelon, which operates the power generating station at Conowingo, will benefit from dredging due to less wear and tear on their hydraulic turbines and improved output. Environmentalists have estimated that Exelon could afford to fund dredging at $27 to $44 million per year out of revenues from selling hydroelectricity.  Yet, Exelon did not cause the problem. The dam didn't cause the sediment to flow into the river. It was allowed to run off by poor land management practices. Some silting does occur naturally, but the lack of attention to stormwater management and soil conservation is largely to blame for the rate of buildup. Maryland is taking on the job of dredging, but Pennsylvania should be the ones paying for it. Pennsylvania loses twice as much sediment to the Chesapeake Bay watershed as Maryland. They are not on track to meet their 2017 TMDL target for sediment and have not even committed to doing so.

Just the 25,000 cu. yd. dredging (representing 1% of the total targeted for removal) in the pending demonstration project entails removing 80 million lbs. of sediment. To stop the buildup in Conowingo Reservoir and carryover into the bay, removal would have to proceed at nearly 30 times that rate, i.e. the annual total sediment flow for Pennsylvania (2.4 billion lbs). Should dredging stop after reaching the target amount, the reservoir will refill in a few years.

Pennsylvania cannot be expected to eliminate all of their sediment runoff. Their target is 1.945 billion lbs. of sediment flow per year by 2025, which would equate to about a 55 million lb. per year annual reduction. This means that interstate nutrient trading would not begin to pay for the 8 billion lbs. of  dredging necessary to correct the problem.

Once we dredge Conowingo Reservoir (and I'm afraid Marylanders will be stuck with the bill) , there are two other dams upstream that have the same problem. Pennsylvania should work on those, too. Exelon's bid for a new 46-year lease to run the hydroelectric station should be rejected unless they offer to foot the dredging bills (not to exceed $44 million/yr) as long as they hold the lease. If they do not, as soon as dredging is substantially complete, perhaps we should prepare to dismantle each of these dams. It would ultimately restore the lower Susquehanna River and ensure that we do not have to keep paying the piper.

A Passable Stream

I have pleasant memories of the street near my grandfather's southern California ranch bordered by a three-foot wide concrete lined drainage ditch. Though I now live in a residential area that borrows its name from western ranch culture, we don't do gutters here much. Instead, we have some stormwater management ponds, lots of woods, and drainage ditches that are pretty much out of sight and mind. Fifty years has taken a toll on many of these ditches, so it may be time to restore them.

The restoration work that would qualify as a Best Management Practice (BMP) is much more than I had envisioned. Whereas my first thought was to simply use several wattles to filter runoff before it reaches the lake, Maryland prefers that long runs be totally retrofitted. An example that bears a strong similarity to one stormwater channel near my land is shown on pg. 60 of this presentation on the topic of Step Pool Storm Conveyances and copied here:

The step pools in the lower photo were created by emplacement of very large rocks and an equal amount of riprap in the stream bed. Underneath is a substantial amount of woodchips and sand mixed together to promote drainage. The banks have been reformed into a wider floodplain, but the stream elevation is unchanged. The engineering behind it all is pretty intense, so taking this on would be a real challenge for me.

Getting someone to fund all this might be a problem, but it is worth taking some time to grind through some calculations to see if the nutrient loading on Lake Lariat (which carries over to the Chesapeake Bay to some degree) could be reduced enough to earn nutrient trading credits. Who knows, the restoration might even pay for itself (besides doing nice things for the neighborhood and the lake). Fortunately, the HOA has equipment that might allow us to do it all in-house.

Wattles could still be the first step. They would be located near the outfall where the channel is shallow. The restoration work could take place upstream of the wattles, which would be useful for a few years and help reduce sediment spilling into the lake during restoration.

Git 'er Done

By Mark Rain

To get them all done in time to avert ecological armageddon, the thirteen prescriptions for healing the planet offered by the concerned scientists who signed the updated warning to the world would require coordination at the highest level conceivable. Coordinating implies a grasp of the larger system effects of any particular activity, prioritizing some over others as needed for the good of the whole. Though strategic coordination is sorely lacking on the environmental front, focused efforts may still help, if not just to allow more time for wiser leadership to ascend.

One of the ominous trends shown in the report is the 75% increase since 1992 in the number of dead zones in the oceans and estuaries.  The supplemental report's description reads,

Coastal dead zones which are mainly caused by fertilizer runoff and fossil-fuel use, are killing large swaths of marine life. Dead zones with hypoxic, oxygen-depleted waters, are a significant stressor on marine systems and identified locations have dramatically increased since the 1960s, with more than 600 systems affected by 2010.

The trend has been nearly linear for the past 50 years, in which about 12 additional aquatic zones have died each year. One of these is the upper Chesapeake Bay where I live. Dead zones are a degenerated condition of algae blooms that rampantly feed on phosphorus and nitrogen, overpopulate, and die, with the consequent breakdown of algal biomass starving the surrounding waters of oxygen and releasing chemical toxins. In 2016, toxins from blue-green algae were found in one-third of lakes and reservoirs in the U.S. One of those was the 90-acre lake in my neighborhood.

Agriculture is blamed for much of the nutrient runoff in the developed world. Fossil-fuel use is also implicated in the report as a cause of dead zones. In less developed areas, sewage is the main contributor. In that respect, my neighborhood belongs to the less developed category. With 4,500+ homes on 6 square miles of hilly land, the number of septic systems overloads the watershed.

While hilly land promotes more runoff, it may also be key to a solution. Most of the runoff does not flow directly into the lake, but into ravines that eventually empty into the lake. My idea to lessen the amount of nutrients in the lake is to install filtration wattles not along the entire lakefront, but one wattle per ravine at the endpoint of contributing septic drainage. Using a mixture of biochar and ablated clays, zeolites, vermiculite, and possibly peat, wood chips, mushroom spawn, or compost, the wattle can be imbedded at the surface of the streambed. This would be done initially at several of the largest ravines with test filters which could be used to measure phosphorus buildup after a year. The ravines with the largest amounts of phosphorus in their test filters would then receive a larger number of wattles to capture the major nutrient flows. I am hoping to get a grant to execute this plan, possibly teaming with a local biologist and academia as an innovative research project. Without funding, I could probably perform a limited version of the plan.

For those whose decisions lack global reach, thinking globally and acting locally at least gains you some cred, raises awareness, encourages replication, and offers the consolation of confronting the world's problems, though they may seem to mount. As one's credibility grows, one can possibly take a leadership role which could involve less hands-on implementation and more coordinating. I am not knowledgeable enough to adjudge priorities between the thirteen global solutions recommended by the thousands of scientists who issued the warning, but that doesn't stop me from taking action at a local level.

The Chesapeake Bay in Greater Peril Than Ever

While the estuary on a stick known as Maryland girds for legal battles over continuing the federal program to restore the Chesapeake Bay, the global force of climate change will increasingly hamper the region-wide effort even if the program ends up being fully funded in the official federal budget.

We are already able to discern the impacts of climate change on the Chesapeake. For example, though most of the world is losing access to water, the northern Chesapeake Bay area where I live has gained 6.6 inches of annual precipitation over the last century. In some respects, this is beneficial, but the major negative effect of more heavy rain is runoff into the bay and its tributaries, causing pollution by nutrients and sediment. This is exacerbated by urbanization throughout much of the watershed. Building codes and local governments are racing to keep up with the problem of stormwater runoff caused by development.

Rising temperatures affects a number of other aspects of the bay ecosystem. One is the profusion of Vibrio bacteria which spreads cholera and a similar disease either by ingestion or through skin lesions.

Before President Blowhard dispenses with climate change throughout the executive branch, government-funded scientists are valiantly assembling reports explaining its observable and anticipated effects. With the amount of rainfall increase we have observed with just a 1.5 C temperature increase, it seems that we should expect significantly more in the coming decades if global temperatures continue to go up exponentially.

From Albert Bates at The Great Change

The graph here shows a generic temperature curve along with several global macronomic indicators modeled in the Limits to Growth study. You might note that the human population is expected to drop in about thirty years (as food becomes too scarce) and think that this will flatten the temperature curve, but there is a delay between cause and effect in global warming as vertically circulating ocean currents cycle over a millennium meaning that increases in ocean temperatures and release of dissolved CO₂ will not achieve their full effect on the atmosphere until decades after the greenhouse effect is arrested by lowering atmospheric carbon.

Bottom line: we can't restore the bay by taking our current inadequate measures. Rising atmospheric temperatures make it necessary to exercise even more severe measures to avoid pushing the bay beyond recoverable limits.  We should not only continue to limit runoff from new and existing development, but we also need to rethink urbanization in terms of permaculture and apply afforestation wherever we can.

Saving the Bay = Saving the Planet

In addition to sequestering carbon, biochar's capacity for reducing nutrient leaching from cultivated land makes it an especially valuable weapon against global warming around estuaries like the Chesapeake Bay. Other measures are necessary, but in terms of longevity, they are band-aids compared to biochar.  Biochar can throw global warming a one-two punch when prodigiously applied in the Chesapeake's watershed. The carbon sequestration aspect is pretty straightforward, but the nutrient leaching/global warming connection needs more explanation.

In spring and summer, the Chesapeake Bay, due to seasonal changes in its upper and lower water density profiles, is a storehouse of methane-generating detritus in its cold, dense, oxygen-starved lower strata. As hurricane season swings into full gear in mid-summer, a strong storm can bring about the phenomenon know as wind set-up which pushes water level higher on the western shore of the bay and an upwelling of water from the lower layer, pulling methane from the underneath the pycnocline and bringing it to the surface.

From Chesapeake Bay: Introduction to an Ecosystem, Chesapeake Bay Foundation, 1995.

Research by Laura Lapham, Lauren Gelesh, Kathleen Marshall, and +William Boicourt published in February under the title "Methane concentrations increase in bottom waters during summertime anoxia in the highly eutrophic estuary, Chesapeake Bay, U.S.A.", hypothesizes that the methane in the sediment begins to escape into the water and collects under the pycnocline where conditions are anoxic enough to prevent it from oxidizing into more benign substances. When a storm comes through before the methane has a chance to mix with upper layers in the cooling autumn, the sudden upwelling of this methane sends a portion of it into the atmosphere.

We already know that estuaries throughout the world contribute something like 3% of total methane to the atmosphere without the large pulses just described. In such an event, however, the Chesapeake Bay (the U.S.A.'s largest estuary) could almost double that figure, were all the sub-pycnocline gas bubbles to escape. Hurricanes and tropical storms have impacted my Maryland home near the Bay about once every three years, of late. It is worth considering that major storms in late summer, when methane buildup is at its peak, may cause methane bursts of this magnitude.

To grasp the magnitude of such an event, let's say just one-third of the Bay's methane inventory were to bubble out during a major storm in mid-August. That would be 47 times the amount released over a 100 day period in the Aliso Canyon natural gas leak!  (Aliso Canyon incident emitted 0.1 Tg. - the largest such leak ever in the U.S.  Based on annual total worldwide CH4 emissions of 469 Tg, a 1% increase from Chesapeake Bay would be 4.7 Tg.)

We cannot shift the burden of climate change to ocean estuaries and blame the Chesapeake Bay for emitting all these greenhouse gases. These episodes would not occur if the Chesapeake Bay were in a healthy condition in which the lower strata maintained adequate oxygen year-round. This is anthropogenic and the cause is mainly excess nutrients and uncontrolled runoff. The tendency of storm intensity to increase as global temperatures warm also gives this punishing sequence of events a positive feedback quality. To stop it, we need to not only think about how to reduce the concentration of atmospheric CO2, but also how to clean up the water draining into our major estuaries.

Your Own Little Rainforests

Lawns do a fair job of capturing runoff, but just putting an average-sized house on a lot can double the amount of runoff from that property. Much of that increase is channeled to gutters and then downspouts, at which point an owner can take a number of further measures to reduce problems downstream. Outlets from downspouts, be they splash blocks or French drains will often evince erosion where the water is let loose to run freely on the soil. This is the place to intervene with a rain barrel and/or a swale. These may still lead to erosion wherever the water discharges, so a garden can be added to infiltrate the excess.

By concentrating the captured runoff, areas of Maryland properties typically receiving 44 inches of rainfall per year can easily get double that amount, making them like miniature rainforests.  Forest gardens are very good absorbers of groundwater, as are rain gardens.

Photo by Dion Gillard

One of my rain barrels discharges through a 25 foot garden hose into a French drain which discharges to a rock filled swale that empties into a rain garden 80 feet from the house. That easily meets the minimum distance requirement of 15 feet from the foundation and is also at a low point on the corner of my property. The rain garden contains a good deal of biochar and compost and I am planning to fill the cracks between the swale rocks with biochar once I obtain plants that grow well in rock gardens. I also have rain barrels for the other three downspouts on my home, two of which are for keeping mushroom logs watered and one for watering the five terraced garden beds in the backyard.

For water coming off an impervious surface such as a patio onto a lawn, a swale or series of them can be added that run on contour. These are interspersed with raised bed gardens that use the water captured by the swales. Yards with slopes up to 33% can use this device, so where such slopes themselves are the source of runoff, these would also be very helpful. The key to making all these alterations efficacious is gardening. To some that may create the impression of unending toil, but it needn't since the gardens will be watered by the rain flowing to them and can be kept moist and fed with the help of biochar.

Charcoalkultur

Infiltration berms belong at the public works level, but a comparable practice for us masses is hugelkultur. I attended a talk last year at the Mother Earth News fair comparing biochar to hugelkultur and discovered that hugelkultur is generally easier and less chancy than making and applying biochar. Yet, a hugelkultur bed will not be as long-lived as one with a load of biochar.

Hugelkultur is the practice of piling soil and organic material on top of a bunch of logs and sticks to form a mound (mainly on contour) which can capture runoff in order to grow plants like a super high raised bed. +paul wheaton published a DVD about it and  +Sepp Holzer put some good instructions on Paul's richsoil website.

I've been using hugelkultur to augment swales in order to reduce erosion on the back slope of my property. My previous post about infiltration berms brought me to consider hugelkultur not as an alternative to biochar, but as another opportunity to put biochar to good use. Filling the gaps with biochar (or some percentage thereof) while building a hugelkultur bed is one way. Biochar could also be applied in areas where there is a need for extra moisture.

Such was the case with my wife's hydrangea which she wanted planted in a sloped area that normally would not stay moist enough for this plant. Yet, there is a roof downspout nearby which spills out onto the slope (via a splash plate) once the rain barrel fills up. I built a quasi-hugelkultur bed to direct the overflow to the hydrangea and loaded the outlet with unground biochar in order to slow the flow of water and hold it close to the plant.

There is enough of a dam behind the biochar to keep it from being washed away. Over time the biochar will break down into small particles and leach into the soil where it can do even more good.

I can see using biochar in a similar fashion on the uphill toe of a hugelkultur bed in order to reduce the tendency of the toe to erode where runoff sheetflow meets the mound. For highly steep slopes (> 25%), a deep swale on the uphill side of the hugelkultur mound containing some percentage of biochar could serve the same purpose.

Swales are an approved ESD practice in the Maryland Stormwater Manual. Hugelkultur beds aren't, but there may be enough latitude in the specs and descriptions that it would fit without requesting special approval. Beyond these practices, terracing is the next step for reducing runoff on steep slopes. For that, heavy equipment is needed, so it's better in most cases to think in terms of swales and mounds.

Filling the Berm

Biochar is well suited to Environmental Site Design (ESD) for stormwater management applications. Its ability to absorb up to six times its weight in water and its long drying time can be used in slowing down runoff to maintain discharge timing while increasing infiltration and evapotranspiration.

Many ESD standard practices include a gravel underlayment to promote drainage. Some of those same ESD practices do not contribute sufficiently to meeting the Channel Protection Volume (Cpv) requirement, i.e. the amount of water that is allowed to run off from a 24-hour one year storm (that is, the average of the largest 24-hour storms historically occurring in an area each year). Since Cpv is sometimes difficult to meet with ESD alone, traditional structural practices must sometimes augment the more distributed ESD practices.

One of the practices that does not contribute to Cpv is infiltration berms. These are long mounds

built orthogonally to the flow of runoff. They consist of 6" of topsoil over an aggregate core. If, like the Stockholm tree planters, we were to load the gaps in the aggregate with biochar, that much more channel protection volume could be earned based on the additional water holding capacity of the biochar.

Of the other practices that already contribute to the channel protection volume, a thick layer of unground biochar between the soil and the aggregate or gravel underneath would help prevent clay particles from blocking the drain, contributing thereby to a more sustainable solution.

Since these two modifications deviate from the specifications in the Maryland Stormwater Design Manual, special review and approval of the innovations would be required at the county and/or state level. MARVALUS Engineering may be the one to request approval of these innovative practices and then earn royalties on their application. Developers and owners probably wouldn't mind paying a small fee along with the price of using biochar if it saves them the expense and real estate of added structural devices or maintenance of the aggregate layer.

Too Big to Swale

Fortunately (and wittingly) we have avoided major overflow incidents from wastewater treatment plants here in Maryland for the past several years. Easier to overlook (and we have) are nonpoint sources of water pollution, which are classified as agricultural, urban, forest, and rural, i.e. septic systems. We have become pretty wise to containing hazardous materials, but the pollutants that are choking our bays and rivers with algae are everyday elements carried in the water seeping through or running over the land. There are over 500 potential water pollutants managed in various parts of Maryland, but one ubiquitous element, nitrogen, is the major problem nutrient feeding the algae invasion of our tidal waters.

Photo by Neil Williamson (CC BY-SA 2.0)

Agriculture is the largest contributor to nitrogen pollution and likely to remain so for many years. This could be because agriculture has consolidated its operations disproportionately to its proper ecological scale. Farms these days, in spite of their vast acreage, are generally family operations. Driven by globalization, agriculture has become a very competitive industry, so much that Maryland farmers would not settle for local administration of their part of the Total Maximum Daily Load (TMDL). They needed more consistent application of the standards that constitute the nutrient diet for the Bay, so TMDL for agriculture is managed at the state level.

However, it is the counties who are responsible for their reducing all of their nutrient flows (including agriculture) below set targets or risk losing their federal funding for infrastructure. In other words, the counties have accountability, but no authority for the behavior of their agricultural sectors. It should be no surprise that they have to shoot beyond their targets in the other sectors in order to make up for the lack of progress by agriculture. (I only have data from St. Mary's County, but am assuming that this subversion of local authority has the same effect everywhere.)

Am I being unfair to the agristocracy? Don't I realize they are working hard to make sure I don't go to bed hungry? No. If anybody has been unfair to them, it's the drafters of the TMDL limits. If those limits are unrealistic or biased, they should be changed. Until then, I'm sticking with my view that Ag is too big to swale and follow other Best Management Practices (BMP's) in fulfillment of their responsibility to help clean up the Bay.

A Way to Plant Free Trees

The erosion control project that I am advocating for my church is to block surface runoff from eroding the topsoil into our detention pond by building a hugelkultur mound on the upper rim of the excavated area. This mound would be planted with a cover crop for at least one season, but after that, it would get some perennials or even trees in places where they wouldn't interfere with future building plans.

I hope we can get started with our preparations soon because we might be able to get help from The Alliance for the Chesapeake's Trees for Sacred Places program, which offers not only free trees, but technical support, training, and religiously-oriented motivation. You just need to have room to plant 60 or more trees. This may be possible, but it would surely fill up our open ground (outside the future building footprint). Teaming with another church congregation to make a total of 60 tree plantings may have to be our approach.

Alliance for the Chesapeake has partnerships with an organization called Interfaith Partners for the Chesapeake, which includes the tree planting program and a new program called RiverWise which looks at stormwater management more broadly, similar to the Watershed Stewards program, and even provides substantial financial assistance to correct problems.

It makes sense to involve church congregations in these efforts. They already have many diligent members who want to be contributors to improving their local communities, but starting with their own properties is a necessary first step.

(Sh)it's All Good

Avian flu is not the only disease that might come from raising chickens.  The common concern is e.coli. Some 60,000 cases of e.coli infections get treated every year in the U.S. and a few deaths do occur, but, though those rates are low, who wants to be sickened by some nasty bug?  Nasty, because the main source is animal excrement.

I could say "shit," but that's not what it is to me.  I treasure it and all other excrement because, in a display of nature's alchemical capabilities, crap can be transformed into black gold through the phenomenon of composting. There are several types of dung I currently collect. We have a backyard chicken owner in our church who lets us take their droppings to our community garden for fertilizer. I regularly visit a riding stables about 3 miles away to fill bags with horse dung and cart them home for composting.

Anyone who has pets can also compost their caca with a little forethought.  I bought a cheap, versatile Geobin composter for the sole purpose of composting the dog mess I clean up weekly. I now look forward to making those weekly rounds, especially with the handy, lightweight poop scooper my wife got for my birthday present. The warnings you hear about keeping pet poo out of your compost bin are valid.  However, once the segregated pet droppings undergo thermogenetic composting at 140 F or higher, and then remain in a pile for a year, they are safe to use in ornamental gardens.  It's this short heat and long cure cycle that keeps the risk of e.coli and numerous other pathogens low. In order to keep the pile from reeking, I simply layer sawdust on top of each week's deposit. I also add meats, fats, and bones from our kitchen scraps to the middle of this bin - another no-no for general composting.

The same approach can even be used for humanure, which requires more planning, preparation, and particularity.  The bins should be built to higher standards, a collection system is needed, and odor control must be thorough.  I'm not there yet, but am headed there.  It's not just about making better soil, it is also about protecting the environment.  Our current sewage systems don't do a good job of this.  Less is more when it comes to giving doo-doo the treatment it deserves.

Maryland's big business-friendly governor doesn't make those Eastern Shore farms compost chicken fecal matter before spreading it on the land.  Yet, another way to deal with pathogens from poultry litter is to make biochar out of it.  There is actually some governmental funding being applied to building up this capability for the sake of the Chesapeake Bay.  Biochar has also recently been ascribed the ability to sequester not only carbon, but e.coli as well.  Simply adding biochar to the soil can protect crops from carrying such pathogens.  It seems that combining thermogenic composting of any form of manure with only 10% biochar by volume would make the resultant product quite safe and result in a double win for the environment.