US Geological Survey Report Cites Declining Ecological Health of Barnegat Bay – Nutrient “Fingerprint” Study Shows Land Use as Primary Source of Pollutant Loads and Small Role For Fertilizers in Total Bay Pollution
Data suggest limited role of fertilizer dwarfed by other sources, primarily development
Gov. Christie’s Management Plan’s Heavy reliance on Fertilizer Law Misplaced
[Intro Note: Here is the most recent and comprehensive scientific review of the efficacy of fertilizer laws in reducing nutrient pollution loads/inputs, from Chesapeake Bay: Recommendations of the Expert Panel to Define Removal Rates for Urban Nutrient Management
The study finds small nitrogen reductions result from fertilizer laws: just 4.5% from the 90% of lawns fertilized by homeowner “do it yourselfers” to a maximum of 20% for high risk laws managed by professionals.
The Report goes on to assume various unverified reductions in total fertilizer sales, in fertilizer use, and in the reduction in nitrogen concentrations – all of which remain unverified by real data in NJ on sales and use.
Of course, the best management approach is to restrict the amount and location of development and to not use fertilizers at all. No development = natural water cycle: recharge & infiltration of rainfall, minimize runoff, wetlands & stream buffers filter pollutants, streams assimilate natural loads.
No development = no homes, no lawns, no fertilizers – no roofs and parking lots, no huge volumes of polluted stormwater runoff. end intro]
The US Geological Survey (USGS) published a Report last year that sought to identify specific sources on nitrate pollution to Barnegat Bay:
I mention this Report now, because I put a call in to Stan Hales of the Barnegat Bay Partnership last week to discuss their numerous objections to Rutgers Professor Mike Kennish’s research that I wrote about earlier in the week (Kennish, among other things, targets land use as the primary source of pollutants harming the Bay).
Before we discussed the status of Kennish’s research, Hales suggested that I review the USGS Report. He implied that it chemically fingerprinted fertilizers as a significant source of nitrogen loadings to the Bay – the inference left unsaid was that the Gov.’s fertilizer law was making progress in reducing those loads.
The USGS Report takes on added relevance right now, because some unnamed State officials have claimed the the fertilizer law signed by Gov. Christie is a significant step in restoring the Bay’s health (i.e. see this Patch story today, which challenges my characterization of the fertilizer law as “largely cosmetic“).
As if we can just keep on building out the watershed, as long as we reduce the nutrient concentrations and use of lawn fertilizer!
(aside from the far greater pollutant loads from development, the fact that if there is no residential development, then there is no fertilizer use is ignored)
[Update – to digress somewhat again, here’s what the Chesapeake Bay expert panel found about the technical basis for fertilizer management programs there, very similar to BBP:
The CBP has had an approved nutrient removal rate for urban nutrient management in effect for nearly 15 years (CBP, 1998, Appendix H). The entire documentation for the rate is provided below:
“… urban nutrient management leads to a reduction in urban fertilizer applied. Urban nutrient management involves public education (targeting urban/suburban residents and business) to encourage reduction of excessive fertilizer use. The CBP Nutrient Subcommittee Tributary Strategy Workgroup has estimated that urban nutrient management reduces nitrogen loads by 17% and phosphorus loads by 22%”
No scientific or modeling analysis could be found to support or document the nutrient reduction rates cited above. In addition, the Panel noted that the definition of the UNM was extremely ambiguous and could not be accurately measured, tracked or verified.
Therefore, the Panel concluded the existing definition and associated removal rates for the existing CBP-approved UNM practice could not be technically justified.” – end update]
The Chesapeake expert panel also found just what I did previously:
In addition, the Panel was concerned about how effectively homeowners and commercial applicators might implement the UNM practices in the real world. Quite simply, what is written in a UNM plan may not be implemented on the lawn. In particular, homeowners may have difficulty in measuring or visualizing what a thousand square feet is, may not calibrate spreaders effectively, or simply want to use up the entire bag of fertilizer product. Similarly, homeowners may elect to follow some UNM practices, but not others, based on personal preferences and other reasons. The Panel concluded that UNM rates should reflect incomplete implementation of UNM plans.
So, let’s get back on point of this post – here are few relevant findings from the USGS Report and observations regarding the fertilizer law:
Citing the prior findings of Dr.. Kennish with respect to eutrophication and the declining health of the Bay, USGS reviewed the literature and found:
Physical characteristics of the estuary, including its shallow depth and limited outlets for exchange with ocean water (poor flushing), render it particularly susceptible to the effects of nutrient loading and, over the last few decades, the ecological health of the estuary has deteriorated (Kennish and others, 2007). In particular, the estuary has experienced increases in macroalgal growth, harmful algal blooms, and turbidity, as well as oxygen depletion, declines in harvestable fisheries, and changes in species composition, including decreases in the biomass and size of seagrass beds (Kennish and others, 2007). The estuary has been classified as highly eutrophic based on the National Oceanographic and Atmospheric Administration National Estuarine Eutrophication Assessment (Bricker and others, 1999; Bricker and others, 2007).
Echoing the land use findings of Dr. Kennish’s Report, the USGS data collection found:
Concentrations of total nitrogen in the five streams appear to be related to land use, such that streams in subbasins characterized by extensive urban development (and historical agricultural land use) —North Branch Metedeconk and Toms Rivers—exhibited the highest total nitrogen concentra- tions (0.84–1.36 milligrams per liter (mg/L) in base flow). Base-flow total nitrogen concentrations in these two streams were dominated by nitrate; nitrate concentrations decreased during storm events as a result of dilution by storm runoff. The two streams in subbasins with the least development— Cedar Creek and Westecunk Creek—exhibited the lowest total nitrogen concentrations (0.16–0.26 mg/L in base flow), with organic nitrogen as the dominant species in both base flow and stormflow.
USGS summarized the literature on the sources of total loads:
On the basis of the 2009 estimate, the total annual load of nitrogen to the BB-LEH estuary was calculated to be 650,000 kilograms (kg) N per year. Results of the study indicate that nitrogen transported to the estuary in surface water contributes 66 percent of the total nitrogen load, direct groundwater discharge contributes 12 percent, and direct atmospheric deposition to the estuary surface contributes 22 percent. Total nitrogen yields for basins in the more developed areas (greater than 10 percent developed) were about twice those for basins in less developed areas (less than 10 percent developed).
With respect to the role of fertilizers, USGS did NOT conclude that they were the primary source of nitrogen to the Bay – and that atmospheric devotion – previously claimed by some to be a major source – is NOT a major source:
Measurements of nitrogen and oxygen stable isotope ratios of nitrate in surface-water samples revealed that a mixture of multiple subsurface sources, which may include some combination of animal and septic waste, soil nitrogen, and commercial fertilizers, likely contribute to the base-flow nitrogen load. The results also indicate that atmospheric deposition is not a predominant source of nitrogen transported to the BB-LEH estuary from the watershed, although the contribution of nitrate from the atmosphere increases during stormflow.
The USGS did find that fertilizers were a significant source, but only in groundwater – not surface water or the Bay as a whole – and only in 2 wells:
Groundwater samples collected from five wells located within the BB-LEH watershed and screened in the unconfined Kirkwood-Cohansey aquifer system were analyzed for nutrient and stable isotope composition. Concentrations of nitrate ranged from not detected to 3.63 mg/L, with the higher concentrations occurring in the highly developed northern portion of the watershed, indicating the likelihood of anthropogenic sources of nitrogen.Isotope data for the two wells with the highest nitrate concentrations are more consistent with fertilizer sources than with animal or septic waste.
So, based on the USGS Report, sources of fertilizer pollutant loads to the Bay are far less significant than those from land use and development.
One limitation of the sampling design is that the contributing area for the surface-water samples contained a mixture of land uses and, therefore, a mixture of nitrogen sources. Future monitoring efforts may include stable isotope sampling in smaller sub- basins dominated by single land uses to improve understanding of the relation between specific land uses and their isotopic signatures within the watershed. Analysis of such samples would help to further characterize the relative importance of terrestrial nitrate sources—animal and septic waste, soil nitrogen, and commercial fertilizers—and aid in prioritizing strategies for reducing nutrient loads such as controlling development, reducing application of commercial fertilizers, and implementing stormwater management.
This USGS finding suggests that because fertilizers are a relative small source of total nitrogen to the bay, and because development is the primary source of pollutant loadings, that there is a very limited role for restrictions on the nitrogen content of fertilizers in reducing nitrogen loadings to the Bay.
Management efforts must be far broader than Gov. Christie’s reliance on the fertilizer law. As I wrote:
Regardless of time release or percentage of the nitrogen content, a fertilizer ordinance CAN NOT ADDRESS TOTAL NITROGEN LOADINGS.
On top of this limited role, the strength of the fertilizer law itself is exaggerated:
1) the sponsor of the fertilizer bill Gov. Christie signed, Senator Beck (R-Monmouth) told me to my face, in her office, that Scott’s (the largest fertilizer manufacturer) did not oppose the bill because she had negotiated revisions that resulted in the fact that it would hove no impact – none – on their fertilizer manufacturing.
If negotiations on the bill resulted in a bill that was not opposed by the largest fertilizer manufacturer, and it would have no impact on the fertilizer they produced, how is that something to brag about?
2) I’ve done hypothetical calculations that show that the fertilizer law, because State officials exaggerate its impact, could result in MORE nutrient pollution entering the Bay, not LESS.
This is because if people think that the fertilizer they buy at the store is “weak” (or diluted), they may apply MORE or it and apply it MORE frequently.
Think 3.2% “near beer”. [Or, as the Chesapeake expert panel found:
N losses were also influenced by the type of fertilizer and the number of soluble N applications.
The law may be having this unintended consequence – has anyone provided fertilizer sales and use data BEFORE and AFTER the law?
3) The Rutgers study recommended a set of management requirements unrelated to fertilizer use.
The Rutgers Report stated the State must do FAR MORE than it is now doing – and Dr. Kennish previously testified that Gov. Christie’s Plan had to be “seriously ramped up”.
4) I am not aware of any data that shows that the fertilizer law has had any measurable impact on the nitrogen loadings to the Bay or on reducing the Bay’s eutrophication problems. None at all.
Yes my good friends at Brick Patch, I am a critic, but I deploy science, facts, and the law to expose the policy flaws and failures at DEP – since 1994.
[End note – DEP has failed to protect vegetated stream buffers by upgrading designation to Category 1, which provides protection for 300 foot wide buffers, each side of stream.
Here is the importance of protecting those buffers, from our Expert panel again:
Historically, concerns with nitrogen leaching from lawns have been driven by human health concerns regarding nitrate contamination of drinking water – particularly groundwater supplies. For this reason the concentration of leachate remains a significant concern. When it comes to urban nitrogen load reduction, however, nitrate leaching are not synonymous with total N loads delivered to the Bay. Nitrate leaching introduces soluble nitrogen into subsurface flow paths that may encounter reducing conditions supporting denitrification.
Indeed, the potential for denitrification along subsurface flow paths is a principal nitrogen removal mechanism expected from riparian and vegetated buffers. “
Why aren’t vegetated buffers a focal point?
Compacted soils in the coastal zone would lead to more surface runoff, and thus the buffers (and wetland systems) are even more critical to filter and remove fertilizer nutrient pollutants.
And the role of fertilizers as a percentage of total loadings is limited – again, consistent with USGS findings, the Chesapeake expert panel found:
Recent research indicates that lawns are highly retentive of fertilizer N under typical application rates and lawn conditions. Groffman et al (2004) found approx 75% of fertilizer N was retained in urban lawns monitored in Baltimore. Kaushal et al (2011) used N isotopic ratio signatures to show watershed export of nitrogen is not directly proportional to fertilizer inputs in Baltimore watersheds. Though lawn fertilizer is a significant input to the watersheds, the isotopic signatures of stream nitrogen suggest sewage is a much more significant N loading source than lawn fertilizer.
So, what do we know about leaking sewer pipes and failing septic systems as sources of pollution to Barnegat Bay and what is DEP doing about that?
Finally, as I’ve written for years now, the voluntary BBP program lacks accountability, which the regulatory TMDL would address – again, our expert panel:
Accountability Mechanisms
The Panel concurs with the conclusion of the National Research Council (NRC, 2011) that verification of BMP installation and subsequent performance is a critical element to ensure that pollutant reductions are actually achieved and sustained across the watershed. The Panel also concurred with the principles and protocols for urban BMP reporting, tracking and verification developed by the CBP Urban Stormwater Workgroup (USWG, 2012).
The Panel felt that accountability was especially important for UNM plans since they are not a tangible or structural practice like many other urban BMPs. UNM plans represent a voluntary intention to implement specific lawn care practices in the future, and not necessarily an assurance that they have actually been implemented on the lawn.