Using a Laser Level for Ecological Studies

Swamp Stomp

Volume 14, Issue 14

The Swamp School Guide to Using a Laser Level for Ecological Studies

The use of a survey grade level is critical for obtaining accurate measurements of various biological features, biological benchmarks, etc.  This information is used for many purposes including stream restoration, coastal restoration, wetland restoration, and other design purposes.

There are two types of levels used for construction and design.   The older of the two is known as the Dumpy level.  This level is like a spotting scope with cross hairs.  It is highly accurate (despite its name) and also has an added advantage of being able to measure distance.  However, it does require much more work to operate and is limited to a range of about 30 feet.  It also requires two people to operate.

Laser levels are the other commonly used measuring tool and are a great improvement over the Dumby levels.  The major benefit is that the distance away from the level is pretty much as far as you can see.  This reduces the number of station moves and speeds the process along.  You also only need to have one person to operate the level.

There is a third option which is to use a surveyor total station.  This however, is a very complicated process and usually beyond the level of detail needed for most biological assessments.  A corollary to this is the use of GPS.  GPS is great for x and y coordinates, but it is often meters off on the elevation (z).

Laser Levels

You do not need to spend a lot of money to purchase a quality laser level.  You can often find these for sale in big box home improvements stores and hardware stores.  They are around a couple of hundred dollars.  You can also rent one from a survey supply shop for about $20-$30 per day.  They will also be happy to sell you one if you need to use it more than just a few times.  Survey grade levels are usually in the $500 to $1000 range.  This is worth the investment if this type of work is a regular thing for you.  Also, do not cheap out on the box.  The level will get bounced around so you will need a quality instrument case.  This is sometimes a problem with the home center levels.

The laser receiver is usually included with the laser level.  This is a little box that attaches to the survey rod with thumb screws.  It takes batteries and makes a tone when the laser beam from the level hits it.

You also need legs.  The level should be placed upon a quality tripod.  This is not the same type as you use for a camera.  Survey grade tripods are usually made of wood or aluminum and have steel spikes to set it into the ground.  The legs are adjustable so that you can level your level.  The level should be about chest high when mounted so the tripod needs to be 4-5 feet high when set up.

Next on your shopping list is a survey rod.  You want to get the smallest rod that will serve the purposes of the site work you are doing.  A 12 foot rod is much better than a 25 foot rod if you only need to go up a few feet.  The bigger the rod the more sway you have and the measurements will be less accurate.  However, if you have a steep slope on you site a bigger rod may be necessary.

You will also need a measuring tape or carpenters rule.  It is better to get one that is calibrated to 1/10’s of a foot rather than inches.  The survey rod is almost always in 1/10’s of a foot, however make sure you are not using some sort of metric rod.  That really clean rod in the back of the tool closet that nobody uses might be there for a reason.

Set Up

The first thing that you want to do is take a walk around the area that you need to survey.  You want to find the best place to set up the level so that you do not need to move it more than necessary.  Keep an eye on slope, trees and other obstructions.  The level needs a clear line of sight.  You can clear some of the vegetation away, but it is usually easier to find a spot that would require the least amount of work to get your shots.  The tripod should be set up above the highest point you are going to survey.  You need to include the height of the level receiver on the rod when you are making this estimate.  This translates to about 5 feet above your highest point.  The level needs to be able to “see” the receiver.  If the level is set is too low it will shoot below the receiver mounted on the rod.  You can move the receiver down, but that would require that you recalculate for those shots.

Keep the level in the box until you are ready to place it on the tripod.  Do not attach it to the tripod and then walk around with it.  It should be boxed when moving it around the site.

Set the legs up on as level a surface as you can.  Adjust the legs so that the level mounting plate is fairly level.  You can use a hand level to do this or the bubble level on the laser level itself.

The laser level attaches to the tripod by way of a large screw below the mounting plate.  Do not tighten this too much until you have leveled the level.  There are three or four leveling screws on the level.  There is also a glass bubble level on the mounting plate.  Adjust the leveling screws so that the level is dead on level in all directions.  This will require that you spin the level around and make adjustments.  If you have attempted to level the tripod before you mounted the level, this will go fairly quickly.  It is critical that the level be mounted level.  Otherwise your data is junk.

Instrument Height

There is usually a marking on the level where you should measure downwards to the ground.  We are also going to determine height of instrument using the back site, but you should always measure the distance from the instrument to the ground.  We don’t really use this data, but it seems that it is always done.  It is sort of a cross check.

Backsight

You should place a project benchmark somewhere near the level set up.  This serves as your project control and can be surveyed for real later if you need to derive actual elevation points from your level runs.  This control should be set using a pin, rod, pipe or other relatively permanent maker.  Wooden stakes do not work as they can be easily removed or damaged.

The backsight elevation is any number that makes sense.  The convention is to set it at 100.  You may come back later in drag control onto the site to determine the actual elevation, but that is not necessary for this type of work.

The laser level indicator should be attached to the rod, usually at the tip.  Note the location of the indicator.  For example it is on the rod at 4.5 feet.  Most telescopic rods have a height indicator on the back of the rod.  As you raise the rod the height indicator numbers will change.  Be careful to raise the rod in the proper order.  This varies with some rod types so be sure to check with the manufacturer on the use of the rod.

A Direct Elevation Rod or a “ Lenker Rod ” is the most common type and has numbers in reverse order on an  graduated strip that revolves around the rod on rollers. Figures run down the rod and can be brought to a desired reading—for example the elevation of a point or benchmark. Rod readings are preset for the backsight, and then, due to the reverse order of numbers, foresight readings give elevations directly without calculating backsights and foresights.

Turn the laser on and position the rod on the benchmark and raise the rod until you hear a steady tone.  You will usually hear a slow chip when you are just below the laser bean and a fast chirp when you go past it.  Note the rod reading.  That is your backsight reading.  Add the elevation from the benchmark rod reading and you have your height of instrument (HI).

For example.  Your benchmark is elevation 100.  Your rod reading on that benchmark is 4.06.  Therefore your Height of Instrument (HI) is 104.06’.  Your benchmark elevation should be lower than the instrument ground location.  Otherwise you need to adjust the detector and do some more math.   It can be done, but it takes more time.

Now you are ready to go to work on the foresights.

Position the rod directly on the ground at each feature shot.  The rod should be straight up and down.  There are plumb levels you can attach to the rod to help you.  Some laser detectors will also beep at you if you are too far out of plumb.

Raise the rod until you hear that steady tone.  Note the rod reading.  Make sure that you raised the rod in the right order and that the numbers are being read correctly.  Usually, this is a matter checking reality.  If your rod reading suddenly jumps by 5 feet from the last point you may have raised the rod sections in the wrong order.

Record each feature and provide some notes.  A level book works great for this.  This is an example of a level book set up.

Set  Up  1

Station

BS

HI

FS

Elev

Notes

(feet)

(+)

(-)

4.06

104.06

100

Benchmark

6.63

0+25

97.43

MT

5.35

0+50

98.71

MHW

At each feature subtract the foresight (FS) from the Height of Instrument (HI) to derive the elevation.

In this example we have a 1.28’ difference from mid tide (MT) to Mean High Water (MHW).  We can therefore assume that our total tidal exchange would be 2.56’ from Mean Low Water (MLW) to MHW.

We would need to check many other points.  Usually for a biological benchmark survey we would to stationing along a cross section.  Each feature would be relative to the feature type and its location on the cross section.  In our example above the distance from the MT to MHW is 25’.  This is measured by setting a fixed staring point at 0+00 and measuring along that line.

If you need to move the level you will need to calculate a new HI.  Make sure to reference the setup with the data.  Start a new table for a new set up.

Finally, if you need to determine the real elevations of your features survey the benchmark.  This will require a surveyor to locate nearby elevation control and drag that onto the site using traverse lines.  You can also use high end GPS for this.  In our example above the real elevation for the benchmark is 456’ NAVD 88.  Our new HI is 460.06.  We need to make sure we cite the vertical data source.  In this case it is North American Vertical Datum of 1988 (NAVD 88).  Therefore our MT is 453.43’ NAVD 88 and the MHW is 454.71’ NAVD 88.  You can do this for all of the data associated with the benchmark.

 One final note of caution

If you are doing level runs for design purposes you may or may not need a licensed land surveyor to sign off on them.  However, if you are doing any floodplain calculation work you will most likely need the help of a licensed surveyor.    Some jurisdictions allow licensed professional engineers to do this as well.  This is a matter of state and federal law so be careful and ask questions.

What happened to the Commerce Clause?

Swamp Stomp

Volume 14, Issue 13

What happened to the Commerce Clause?

I know in last week’s newsletter I promised to go over how to use a level for wetland and stream work. However last Tuesday the EPA and the Corps released a prepublication of the new Waters of the US rules. This past Friday the Corps circulated an internal memo to the field offices about what was going on. So, I thought we might deviate from our level work and jump into these new rules for a bit. Never fear, the official Swamp School Guide to Using a Laser Level for Wetland and Steam Work will be published in next week’s newsletter.

At 370 pages long the new rules weigh in at 2.4 pounds and just shy of an inch thick if you print them double sided. It cost me about $25 just to print them. I did get a little fancy and had them bound, so add another 3 dollars for that.

The stated intention of the new rules is to clearly define what exactly is a waters of the United States. This seems simple enough. Not really. This has been that focus of a number of Supreme Court cases over the last couple of decades. The most infamous is the Rapanos and Carabell case of 2006. This brought us new concepts like significant nexus and traditional navigable waterways. Everyone has been confused ever since. So it is not necessary a bad thing to try to clear this up.

However, there is the issue of what makes the federal government think it has the right to tell someone what they can or cannot do on their land. If that land is a waters of the US pay attention to the “of the US” part. That means it is within the federal governments purview or shall we say jurisdiction to tell you what you can or cannot do on your land.

How did that happen you ask? It is a little thing called the Commerce Clause found in Article 1, Section 8, Clause 3 of the Constitution of the United States. This clause states that the United States Congress shall have power “To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes.” Courts and commentators have tended to discuss each of these three areas of commerce as a separate power granted to Congress. It is common to see the individual components of the Commerce Clause referred to under specific terms: The Foreign Commerce Clause, the Interstate Commerce Clause, and the Indian Commerce Clause.

The significance of the Commerce Clause is described in the Supreme Court’s opinion in Gonzales v. Raich, 545 U.S. 1 (2005):

“The Commerce Clause emerged as the Framers’ response to the central problem giving rise to the Constitution itself: the absence of any federal commerce power under the Articles of Confederation. For the first century of our history, the primary use of the Clause was to preclude the kind of discriminatory state legislation that had once been permissible. Then, in response to rapid industrial development and an increasingly interdependent national economy, Congress “ushered in a new era of federal regulation under the commerce power,” beginning with the enactment of the Interstate Commerce Act in 1887 and the Sherman Antitrust Act in 1890.”

The interpretation of the Commerce Clause has helped define the balance of power between the federal government and the states and the balance of power between the two elected branches of the Federal government and the Judiciary. As such, it has a direct impact on the lives of American citizens.

The Commerce Clause has been used to identify what waters are subject to regulation by the federal government. In the United States v. Rands, 389 U.S. 121 (1967), the 1967 Rands decision states:

“This power to regulate navigation confers upon the United States a dominant servitude, FPC v. Niagara Mohawk Power Corp., 347 U.S. 239, 249 (1954), which extends to the entire stream and the stream bed below ordinary high-water mark. The proper exercise of this power is not an invasion of any private property rights in the stream or the lands underlying it, for the damage sustained does not result from taking property from riparian owners within the meaning of the Fifth Amendment but from the lawful exercise of a power to which the interests of riparian owners have always been subject.”

In 1948 the federal Water Pollution Control Acts was enacted to exercise some federal oversight of state and location actions regarding waters. However, it lacked any authority enforce or permit these activities. It became more of an encouragement rather than an enforcement program. This is why we now have a Clean Water Act.

The existing definition of waters of the US is limited to waters that directly or in some case indirectly affects interstate or foreign commerce. This “commerce connection” is required because the Clean Water Act is limited to those types of waters. Specifically, it is limited to traditionally navigable waters as discussed in the Rapanos case.

However, in looking at some of these older laws it would appear that there may be authority to expand beyond those waters thought to be traditionally navigable. At least the EPA and the Corps think so. Perhaps that is why the legal authority is the Federal Water Pollution Control Act, 33 U.S.C. 1251, et seq. It is generally accepted that the Clean Water Act is a body of amendments to the 1948 law. However, one interpretation of the 1948 law gives the federal government the authority to encourage clean water programs. However, what remains unclear is if this encouragement was codified in the passage of the 1972 amendments known as the Clean Water Act. If this was the case, they why did the Supreme Court limit EPA and the Corps to waters subject to interstate or foreign commerce. I can’t image that they missed this.

Biological Benchmarks

The Swamp Stomp

Volume 14, Issue 12

A biological benchmark is a concept I first ran into while working in the Chesapeake Bay region.  They are used in shoreline restoration using native grasses.  These are often called living shorelines or vegetative erosion control.

The concept of biological benchmarks is based upon empirical data and direct observation of natural plant communities.  The issue relates to specific hydroperiods that the native plants can tolerate.  This results in an establishment of a given plant community based upon a frequency and duration of inundation by water.  Many plant species have highly specific hydroperiod tolerances that can be measured in the field and extrapolated elsewhere.

Source: Wikipedia
Source: Wikipedia

The best example of plants with highly specific hydroperiods  are represented by the coastal Spartina genus.  Two of the Spartina species in particular include Spartina alterniflora (cordgrass) and Sparitna patens (salt hay).  Both of these species occur in the intertidal zone and are found all along the east coast and the Chesapeake Bay.  They are salt marsh grasses and also tolerate some salt water.

What makes the two species of Spartina unique is that they only grow in two very distinct regions of the intertidal zone.  S. alteniflora is found between mid tide (MT) and extends up to mean high water (MHW).  S. patens picks up from there and occurs between mean high water (MHW) and mean high high water (MHHW) or spring tide.  What is amazing about this is that both of these species do not vary more than 0.1 feet in elevation from these tidal zones.  They are very precise about where they will live.

To establish our biological benchmarks we need to make sure that our study area is not under any major stress.  This mostly comes in the form of bank erosion and herbivory.  If either of these is excessive the area may not yield accurate results.  I also use a fetch rule of thumb.  Fetch is the distance from the shoreline across open water.  This is measured perpendicular to the shore line.   If the fetch is more than one (1) mile, I do not consider the site suitable for further study.  The wave action is just too great.  High boat traffic can also be a problem.  What usually happens in this circumstance is that my mid tide elevation is missing.

Once we have satisfied the disturbance issue we can start measuring.  We need to take a number of elevation shots using a level of the extreme limits of both the S. alterniflora and S. patens.  This is usually done using a laser level.  First establish and back site a site benchmark.  Get your instrument height and then you are ready to start measuring  fore site elevations.  Each fore site shot should be corrected and converted based upon the site benchmark.  I usually set this at elevation 100.  I will cover how to do this in next week’s newsletter.

You should see a consistent range of elevations that can be extrapolated to MT, MHW and MHHW.  This can be cross checked against the published tide tables for your region.   If you have a two (2) foot tide range then the elevation change from MT to MHW should be one (1) foot in height.  The cordgrass should confirm this.

You may ask why all the bother if we have the tide tables?  The answer relates to tidal restrictions and local variations.  The tide tables will tell you what the exact elevation is at a given tide gauge.    However, in survey terms you would need to drag that control across the water to your site.  If there are no restrictions and you are relatively close to the gauge you may be able to do this.   However, one bridge or culvert between you and the gauge can have a dramatic effect on the tidal exchange.

I had a project in upstate New York on the Hudson River that had a major problem with tidal restrictions.  It was a freshwater tidal marsh and had about a 1.5 foot tidal exchange at the gauge near West Point, NY.  The gauge was across the river but close by.  The marsh restoration designers had based there plant species selection and placement based upon the use of the gauge.  Unfortunately, they missed the fact that there was a railroad crossing bridge between the marsh and the river.  The bridge impinged the tidal flow into and out of the marsh by close to a foot.  The result was that the tidal exchange inside the marsh was about 0.75 feet rather than the calculated 1.5 feet.   Now this may not sound like a big difference, but it would result in the marsh planting being placed about a foot above the waterline.  This would be bad as the plats were all emergent species and required frequent inundation.  That is hard to do if you are a foot above the waterline.

Biological benchmarks saved the day.  We were able to establish the proper elevation for the new marsh based upon the observed limits of a few selected freshwater tidal species.   There is a species of Typha that is unique to the region that served as a great biological benchmark indicator species.  The end result was the design was lowered by about a foot and all the plants are happy.

The trick to all of this is the need to understand what the plants require.  Once you understand what the plants need the rest falls into place.

Have a great week!

Marc

Stock Ponds and the EPA

The Swamp Stomp

Volume 14, Issue 11

We have another wetland violation case to talk about.  This story broke last week and is about a small landowner, Mr. Allan Johnson who had built a stock pond on his property.  The case has not gone to court, but in an unusual turn of events three US Senators offered to help Mr. Johnson by sending a strongly worded letter to EPA.

So here is what happened.  Mr. Johnson owns a small 8-acre farm in Wyoming.  He wanted to construct a stock pond on his property and went to the state for the required permits.  No you may ask, why did he not go to the Corps or EPA?  The answer is that under Section 404 (f) (1) (c) stock ponds are exempt.  The reason they are exempt relates to water quality impairment.  If it is determined that there is no degradation to water quality then they fall under the farm exemption.  This determination is made by the state.  He did go to them.

This is the current Clean Water Act rule on this point.

Clean Water Act Section 404 (f)(1)(c)

(f) (1) Except as provided in paragraph (2) of this subsection, the discharge of dredge or fill material –

(C) for the purpose of construction or maintenance of farm or stock ponds or irrigation ditches, or the maintenance of drainage ditches;

(2) Any discharge of dredged or fill material into the navigable waters incidental to any activity having as its purpose bringing an area of the navigable waters into a use to which it was not previously subject, where the flow or circulation of navigable waters may be impaired or the reach of such waters be reduced, shall be required to have a permit under this section.

Back before the new EPA rules started floating around the state made the water quality calls.  This was something called a section 401 water quality certification.  I used the term “was” because under the new rules it does not seem that the state needs to get involved anymore.  EPA has it covered.  Separation of powers is so inconvenient and inefficient.  Sorry,  I digress.

In 1987 the Corps had issued a now expired regulatory guidance letter (RGL) that detailed the terms and conditions in which a stock pond would be exempt.  Its focus was on the physical extent of the pond and how it was to be used.  The Corps was concerned about the construction of the stock pond for other uses such as residential amenities.   There is a quote that is worth mentioning.

“For Section 404(f)(2) to apply, the construction or maintenance activity must bring a water into a use to which it was not previously subject and impair the flow or circulation or reduce the reach of such waters. Both of these determinations are judgment calls which must be made in a reasonable fashion. It could be argued that one shovel-full of material placed in waters of the U.S. would reduce the reach. Such an argument is not reasonable and would defeat the purpose of the exemption. “

However, the RGL is no longer in use.  The impacts to the streams became the new focus of the Corps, but the exemption till remains today.

So how are the waters deemed impaired?  That is up to the state.  Section 401 of the Clean Water Act is all about the states roles in deciding water quality impact.  Sections 404 only deals with discharge of dredge and fill material.  This has just become a state’s rights issue.  By the way, Mr. Johnson received all of the required state permits.

So what is a stock pond?

A stock pond is nothing more the blocking up of a small stream to create a pond.  These are often referred to as farm ponds.  There is usually some excavation to deepen the pond.  In order to fall under the exemption, the pond must serve an agricultural purpose.  Activities such as irrigation, live stock watering, and minor flood controls are all examples of stock ponds.  They can also serve some passive recreational uses such as a fishing hole or swimming pond, but that cannot be their main purpose.

So what went wrong?

On January 30, 2014 the US EPA issued a compliance order stating that Mr. Johnson placed fill material into a waters of the US.  On October 11, 2012 the US Army Corps of Engineers conducted a site inspection of Mr. Johnson’s pond.  They found that approximately 12 cu yards of material was placed below the ordinary high water mark of Six Mile Creek.  The Corps further estimated that 40 feet of stream was filled and an additional 745 feet of stream was inundated by the new pond.  On October 26, 2013 the Corps notified Mr. Johnson that a standard Clean Water Act permit would be required.  Can we assume that means a nationwide permit?

It does not appear the Mr. Johnson responded to the Corps.  However, in numerous news articles about this case he has stated that he contacted the state engineer and received the necessary state permits.  As a result on February 7, 2013 the Corps turned this case over to EPA for enforcement.  In case you were wondering how the Corps enforces wetlands cases now you know.  They do not.  The EPA does.

On May 20, 2013 the USEPA conducted a site inspection of the pond and found that the 40 foot stream reach was impacted by the pond dam and that 785 feet of stream (40 feet more) had been impacted by the pond.  Maybe it rained.

Now there are several troubling points about this case.  First was the Corps or EPA invited onto Mr. Johnson’s property?  If not, did they have a warrant, signed by a judge?  Neither the EPA nor the Corps can enter onto a property unless they have probable cause and this may still require a written warrant.

The second point is related to the Sackett case two years ago.  The EPA is demanding in its compliance order that certain remedies must be implemented or Mr. Johnson faces a $75,000 per day fine.  It is important to note that the Supreme Court unanimously found in the Sackett case that the EPA must follow the Administrative Procedures Act rules with regards to 404 violation cases.  The compliance order does mention this as the very last item.  The good news is that he can bring this case to a judge ahead of an enforcement action.

The EPA did state in its compliance order that Mr. Johnson should retain the services of a consultant to determine if the waters in question are waters of the US.  Unlike the Sacketts, I do not think this is in dispute.  Rather, the issue is the type of device that he constructed.

This brings me to my final point.  The entire issue is related to whether Mr. Johnson built a stock pond or a dam.  I do not know how you build a stock pond without a dam so I can easily see his point.  However, what concerns me is the fact that there was some sort of state approval of the structure. Presumably, the state felt it was a stock pond.  Under the rules for stock ponds a state permit is required.  By all accounts, Mr. Johnson followed those rules.  Is the State of Wyoming’s determination that this is a stock pond in question?  If so, should the violation be directed at the state?  Can EPA override the state’s determination right now?

Coming Soon to a Farm Near You

Don’t worry, once the new waters of the US rules go into effect this issue will be crystal clear.  The state will have no say in the matter and Mr. Johnson is looking at some major fines.

Keep an eye our for the new rules.  This is an example of what is coming.

2014 EPA Water Rule Changes

The Swamp Stomp

Volume 14, Issue 10

As of the end of 2013, the US EPA has announced 134 new and modified agency rule changes.    It is a health list when compared to the 53 new rules in 2012.  They have been quite busy.  The rules are separated into major areas that include: air, chemical safety, solid waste and water.  The vast majority of these new rules are focused on greenhouse gas emissions, client change and the like.  However, water issues are quite significant.  There are 14 new water rules under consideration and include the definition of “Waters of the United States” Under the Clean Water Act.

To help you sort though all of this I have included the 14 water rule changes along with a brief summary of each one.

epa

Pre-rule Stage

RID:  2040-AF43

Title:  NPDES Regulations to Address Water Quality Impacts from Forest Road Discharges

Summary:  The EPA is exploring the use flexible non-permitting approaches under the Clean Water Act to regulate certain discharges of stormwater from forest roads, including logging roads, in order to address water quality impacts from those discharges. The EPA recognizes that effective best management practices (BMPs) exist that protect receiving waters and minimize impacts. The EPA is considering approaches that leverage effective BMP programs.

RID:  2040-AF46

Title:  Section 610 Review of National Pollutant Discharge Elimination System Permit Regulation and Effluent Limitations Guidelines Standards for Concentrated Animal Feeding Operations

Summary:  The EPA promulgated revised regulations for Concentrated Animal Feeding Operations (CAFOs) on February 12, 2003 (68 FR 7175). The “2003 CAFO Rule” expanded the number of operations covered by the CAFO regulations and included requirements to address the land application of manure from CAFOs. The 2003 CAFO Rule required all CAFOs to seek NPDES permit coverage.

Proposed Rule Stage

RID:  2040-AD39

Title:  Uniform National Discharge Standards for Vessels of the Armed Forces – Phase II

Summary:  CWA section 312(n) directs EPA and DoD to establish national discharge standards for discharges incidental to the normal operation of a vessel of the Armed Forces. The proposed standards will apply to approximately 6,000 vessels of the Armed Forces and are intended to reduce the adverse environmental impacts associated with the discharges, stimulate the development of improved pollution control devices, and advance the development of environmentally sound ships by the military.

RID:  2040-AF03

Title:  Development of Best Management Practices for Recreational Boats under Section 312(o) of the Clean Water Act

Summary:  The Clean Boating Act amends section 402 of the Clean Water Act (CWA) to exclude recreational vessels from National Pollutant Discharge Elimination System permitting requirements. In addition, it adds a new CWA section 312(o) directing EPA to develop regulations that identify the discharges incidental to the normal operation of recreational vessels (other than a discharge of sewage) for which it is reasonable and practicable to develop management practices to mitigate adverse impacts on waters of the United States.

RID:  22040-AF16

Title:  Water Quality Standards Regulatory Clarifications

Summary:  EPA proposed changes to the water quality standards (WQS) regulation to improve its effectiveness in helping restore and maintain the Nation’s Waters. The core of the current WQS regulation has been in place since 1983.  These revisions will allow EPA, States, and authorized tribes to better achieve program goals by providing clearer more streamlined requirements to facilitate enhanced water resource protection.

RID:  2040-AF25

Title:  National Pollutant Discharge Elimination System (NPDES) Application and Program Updates Rule

Summary:  EPA plans to propose regulations that would update specific elements of the existing National Pollutant Discharge Elimination System (NPDES) in order to better harmonize regulations and application forms, improve permit documentation and transparency, and provide clarifications to the existing regulations. In this effort EPA plans to address application, permitting, monitoring, and reporting requirements that have become obsolete or outdated due to programmatic, technical or other changes that have occurred over the past 35 years.

RID:  2040-AF30

Title:  Definition of “Waters of the United States” Under the Clean Water Act

Summary:  After U.S. Supreme Court decisions in SWANCC and Rapanos, the scope of “waters of the US” protected under all CWA programs has been an issue of considerable debate and uncertainty. The Act has a single definition for “waters of the United States.” As a result, these decisions affect the geographic scope of all CWA programs. SWANCC and Rapanos did not invalidate the current regulatory definition of “waters of the United States.” However, the decisions established important considerations for how those regulations should be interpreted, and experience implementing the regulations has identified several areas that could benefit from additional clarification through rulemaking. U.S. EPA and the U.S. Army Corps of Engineers are developing a proposed rule for determining whether a water is protected by the Clean Water Act. This rule would make clear which waterbodies are protected under the Clean Water Act.

RID:  2040-AF48

Title:  Guidelines Establishing Test Procedures for the Analysis of Pollutants Under the Clean Water Act; Analysis and Sampling Procedures

Summary:  This regulatory action would amend “Guidelines Establishing Test Procedures for the Analysis of Pollutants” at 40 CFR part 136 to approve test procedures (analytical methods) for use by testing laboratories for water monitoring. These test procedures are used to implement the National Pollutant Discharge Elimination System (NPDES) program unless an alternate procedure is approved by a Regional Administrator. The regulation would also revise, clarify, and correct errors and ambiguities in existing methods and the water monitoring regulations.

Final Rule Stage

RID:  2040-AC84

Title:  National Pollutant Discharge Elimination System (NPDES): Use of Sufficiently Sensitive Test Methods for Permit Applications and Reporting

Summary:  EPA is launching an effort to update specific elements of the existing NPDES regulations in order to provide clarifications related to the NPDES permit application and NPDES permit monitoring analytical detection level requirements.

RID:  2040-AE95

Title:  Criteria and Standards for Cooling Water Intake Structures

Summary:  Section 316(b) of the Clean Water Act (CWA) requires EPA to ensure that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available (BTA) for minimizing adverse environmental impacts. Under a consent decree with environmental organizations, EPA divided the 316(b) rulemaking into three phases. All new facilities except offshore oil and gas exploration facilities were addressed in Phase I in December 2001. In July, 2004, EPA promulgated Phase II which covered large existing electric generating plants. In July 2007, EPA suspended the Phase II rule following the Second Circuit decision.  In light of the Supreme Court 2009 decision and its recognition that EPA has broad discretion in its 316(b) regulations, EPA initiated consultation with the Fish and Wildlife Service and the National Marine Fisheries Service under Section 7 of the Endangered Species Act. EPA and the Services began informal consultation in 2012, but concluded in 2013 that formal consultation was necessary. In order to accommodate the regulatory 135-day time frame for formal consultation, plaintiffs agreed to a modification to the settlement agreement, extending final rule deadline to November 4, 2013.

RID:  2040-AF14

Title:  Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category

Summary:  EPA establishes national technology-based regulations, called effluent limitations guidelines and standards, to reduce discharges of pollutants from industries to waters of the U.S. These requirements are incorporated into National Pollutant Discharge Elimination System (NPDES) discharge permits issued by EPA and States and through the national pretreatment program.

RID:  2040-AF21

Title:  Water Quality Standards for the State of Florida’s Estuaries and Coastal Waters

Summary:  EPA is under a Consent Decree deadline to sign a notice of final rulemaking for numeric nutrient water quality criteria (which are elements of water quality standards) for the State of Florida’s estuaries and coastal waters by September 30, 2013. Pursuant to a judicial order, EPA’s obligation to sign a notice of final rulemaking for numeric nutrient water quality criteria for flowing waters in south Florida (including canals), tidally influence segments, and the downstream protection values for flowing waters into estuaries by September 30, 2013 has been stayed until 30 days after the court rules on EPA’s motion to modify the Consent Decree to relieve EPA of its obligation to finalize criteria for those waters.

RID:  2040-AF39

Title:  Water Quality Standards for the State of Florida’s Streams and Downstream Protection of Lakes: Remanded Provisions

Summary:  This final rule addresses an order by the U.S. District Court for the Northern District of Florida from February 18, 2012, which remanded to the EPA two portions of its numeric water quality standards for nutrients in Florida that were promulgated and published on December 6, 2010. This rule promulgates criteria for the remanded provisions and provides additional explanation: the flowing waters criteria derived using the reference condition approach for Florida streams and for the derivation of the downstream protective values (DPVs) for unimpaired lakes. Per the terms of the Consent Decree, EPA signed for publication in the Federal Register proposed criteria on November 30, 2012.

RID:  2040-AF44

Title:  Effluent Limitations Guidelines and Standards for the Construction and Development Point Source Category

Summary:  This action will address revisions to the effluent guidelines and standards for the construction and development (C & D) point source category 40 CFR 450. The C&D rule was issued on December 1, 2009 and became effective on February 1, 2010. This action would revise several of the non-numeric portions of the rule in response to litigation.

 

Plant Community Mapping

Swamp Stomp

Volume 14, Issue 9

One of the biggest challenges to new delineators and even some experienced wetland delineators is getting the plant community mapping done right.  This is a very important task as it serves as the basis for where and why the wetland sampling points are located where they are.  As you may recall the US Army Corps of Engineers Wetland Manuals require that each plant community should be represented by a sampling point.

The new Regional Supplements are really not much help on this.  They do describe in very generic terms what some of the common plant communities in the region and even sub-region are.  For example this is from the Eastern Mountains and Piedmont Regional Supplement.

Northern Mountains and Piedmont (MLRAs 147 and 148 of LRR S)

This subregion includes the northern Appalachian ridges and valleys (MLRA 147) and the northern Piedmont (MLRA 148). The ridge-and-valley portion is underlain by Paleozoic sandstones, conglomerates, limestones, and shales, whereas the Piedmont portion is underlain by generally older metamorphic and igneous rocks. The central portion of the Piedmont also contains sandstones, conglomerates, and shales that were laid down in the ancestral Atlantic Ocean during the Triassic period. Average annual rainfall over most of the subregion ranges from 31 to 52 in. (785 to 1,320 mm), and average annual temperature ranges from 44 to 57 °F (7 to 14 °C) (USDA Natural Resources Conservation Service 2006).

 

Only about 55 percent of the ridge-and-valley portion of the subregion and 25 percent of the Piedmont portion are forested today. Agricultural and urban development makes up the remainder of the subregion. Common tree species in forested areas include white oak, black oak, northern red oak, bear oak (Q. ilicifolia), chestnut oak, American elm, hickories, tuliptree, Virginia pine, pitch pine (P. rigida), eastern redcedar, and other species (Society of American Foresters 1980; USDA Natural Resources Conservation Service 2006).

As you can see there is a general description of the trees found in the region.  However, there is not much else.  In this example understory species are not mentioned and there is no discussion of the other plant communities in this area.  The Corps goes on to later extol the need to identify the plant communities.

“The manual uses a plant-community approach to evaluate vegetation. Hydrophytic vegetation decisions are based on the assemblage of plant species growing on a site, rather than the presence or absence of particular indicator species. Hydrophytic vegetation is present when the plant community is dominated by species that require or can tolerate prolonged inundation or soil saturation during the growing season.”

So getting this right is very important.  To help you with this I have a few tips and tricks to get you started.

First, you need to identify a plant Community text for your region.  For example in North Carolina, Classification Of The Natural Communities Of North Carolina Third Approximation, by Michael P. Schafale and Alan S. Weakley (1990) is a great reference document for understanding how these plant communities are distinguished.

This is an example of a portion of the vegetation description for a specific plant community.  There is actually quite a bit more that is present and is very useful.  Location, geology, soils and other features are described relative to this community type.

Carolina Hemlock Bluff

Vegetation: The canopy is generally well developed, though not always closed, owing to extreme rockiness and steepness. Tsuga caroliniana is the dominant trees; species such as Quercus montana (prinus), Pinus rigida, Pinus pungens, Quercus rubra, or Tsuga canadensis often occur. Undergrowth is generally a dense layer of heaths, especially Kalmia latifolia, Rhododendron catawbiense, Gaylussacia spp., and Vaccinium spp. The herb layer is very sparse below the dense shrub growth. Species may include Gaultheria procumbens, Mitchella repens, Chimaphila maculata, Galax urceolata (aphylla), Xerophyllumasphodeloides, and Trilliumundulatum. Bryophytes (Dicranumspp., Leucobryumalbidum, and L. glaucum) and lichens (Cladonia spp. and Cladina spp.) are sometimes prominent.

From this description alone you would be able to develop a plant list and assign wetland indicators.

In just about every state there exists a plant inventory and classification text.  Most of these are published by a state land grant university.  These are usually the major agricultural institutions.   However, in the North Carolina example one professor is from NC State and the other is from the University of NC.  NC State has a major agricultural program.  UNC is more of a research institution.  This collaboration has produced a terrific document and a great example of universities working together.  Just don’t bring up basketball.

I had mentioned a few newsletters ago the Swamp School is launching a new online training program called Virtual Swamp Tours.  This virtual trip to the swamp is intended to show you what these plant communities look like in person.  We hope to have the first set of tours up in a few weeks.  We are also including a sample tour in our hydrology webinar that we are offering next week.

Have a great week!

– Marc

Help the Brown Headed Nuthatch

Swamp Stomp

Volume 14, Issue 8

With the development of new forestry short rotation techniques there has arisen a new concern about the brown headed nuthatch.    These little guys live in mature pine forests and their habitat is declining.  Changes in harvest practices, selling forest land off for development and other pressures have reduced the numbers of acres of pine forest that the nuthatch needs to survive.

The brown headed nuthatch is the least common nuthatch in North America.  Its range is limited to the southeast extending from southern Virginia south to central Florida and west to east Texas.  It prefers softwoods like loblolly or long leaf pine forests.

Source: Wikipedia
Source: Wikipedia

This nuthatch has a few peculiarities.  It uses tools!  It will use a piece of bark to pry up another piece of bark to search for food.  It will often carry this “tool” from tree to tree.   It will also hide its seed cache with a piece of bark.

The brown headed nuthatch and the pine warbler have a sort of Hatfield’s and McCoy’s battle going on in the pine forest.  Both species are competing for the same habit and food.  Flocks of nuthatches will attack the warblers.  But don’t worry the warblers will fight back.  This battle has been going on for thousands of years.

We need your help and we are willing to pay you for it!  We are holding another contest and more details are at the end of this article.

If you live in the southeast could you build a bird box for these guys?  For about $3 in lumber you can make one in about an hour.  The Georgia Department of Natural Resources has a great set of design plans that you can download for free.

You will need one (1) 1”x6”x4’ piece of lumber and a few screws and a 6 penny nail.   I do have a couple of suggestions on the lumber.  Do not use pressure treated lumber.  It contains some pretty nasty salts that will harm the bird.  Pine is the natural habitat for this bird.  It is cheap and easy to find.  The downside is that it will probably only last 2 or three seasons before it rots away.  Rough cut pine is ideal as it simulates the natural nest cavity this bird is looking for.  If you use this, the board you buy will actually be 1”x6” as opposed to the milled lumber that is ½” smaller.  You do not need to trim the board down to use the design plans.  The house will just be a bit wider and I am sure the nuthatch will appreciate the extra space.  If you want a really cool house, try to find a piece of pine with the bark still on it and use that for the front piece.

Don’t forget to pre-drill the screw holes.  The lumber is thin and will split if you do not have pilot holes.

There is a really important aspect to the nuthatch design.  The front opening needs to be a round hole that is 1 ¼” in diameter.  If the hole is too big the bluebirds will move in.  This design is basically the same as a bluebird house with a slightly smaller opening.  As an alternative to building a house yourself you can buy a bluebird house and make a nuthatch adapter by placing a piece of wood with a smaller hole drilled into it over the existing hole in the house.   I have also seen a piece of tin or copper used this way.  Just be sure there are no sharp edges.

Lastly, please do not paint the house.  The nuthatches are looking for tree cavities and you want to simulate these.  Save the ornate painting for the bluebirds.  They are the splashy ones.

The box should be mounted about 5 feet or more above the ground on a tree.  Again, the house needs to look like a tree cavity.  I have seen some on posts, but it should look like a small tree.  You can mount the box higher if you like.  The nuthatches will nest upwards of 50 feet off the ground.

I f you want to keep up with the sightings of the brown headed nuthatch, ebird has a really nice tracking map.   They include hot spots and personal locations.  There is also an iPhone app that is pretty cool for keeping up with all of the birds in your area.

facebookphoto

We have decided to run another Facebook photo contest.  You can win a $10 Amazon Gift Card by entering a picture of one of the following categories:

  1.  A brown headed nuthatch you have seen (original pictures only – no ripping them off the internet)
  2. A picture of the birdhouse you built or bought (It has to be a nuthatch house!)
  3. A picture of you attempting to build a bird house (not all attempts are successful so we wanted to give those that are carpentry challenged a chance)
  4. Non- southeast birdhouse.  If you are not in the brown headed nuthatch region, send in a picture of a birdhouse you have made.  Be sure to include the name of bird you are trying to help.

Each category will be awarded a gift card.  The winner will be selected by popular vote, so once you enter encourage your friends and family to vote for you picture.

Have a great week!

– Marc

Russian Wetlands

Swamp Stomp

Volume 14, Issue 7

In the spirit of the Winter Olympics I thought I would do a little digging on wetlands in Russia.  Russia is the world’s largest county.  According to Wetlands International, the country includes very large areas of wetlands, including peatlands of various types (raised bogs, fens, and transitional mires) covering 1.8 million km2, 120,000 rivers with a total length of 2,300,000 km, 2 million lakes with a total volume of 370,000 km3, and diverse marine wetlands occurring over a 60,000-km stretch of the national coastline.

Since 1975, Russia has been one of the one of the Ramsar countries.  It has designated 35 wetland sites totaling 10.3 million hectares for the Ramsar list.  However, they have also protected areas of wetlands the go well beyond the Ramsar criteria.  Approximately, 9,000,000 ha of wetlands are protected within the strict nature reserves (zapovedniki),  5,300,000 ha, in the federal sanctuaries and wildlife refuges (zakazniki), 650,000 ha, in the national parks, and 60,000,000 ha of wetlands are protected at the local level.

Some of the more significant wetland systems include (From Wetlands International):

  • The Volga Delta, the largest deltaic complex in Europe and one of the richest bird habitat in the world, covering 19,000 km2;
  • Kandalaksha Bay on the eastern side of the White Sea and Lake Khanka in the Russian Far East, renowned for their importance for breeding and migrating waterbirds;
  • The world’s largest peatland system of Bolshoye Vasyuganskoye covering 50,000 km2 in Western Siberia;
  • Lake Baikal containing 20% of the world’s liquid fresh water with its unique fauna characterized by the highest number of endemic species of all the inland water bodies;
  • Large wetland areas along the coasts of the Black Sea and Sea of Azov on the south;
  • Extensive tundra wetlands underlying by permafrost on the north, and many others.

On the plains of Western Siberia, a continuous bog landscape is found, with a great number of lakes and wide river valleys. This area comprises a great ‘duck factory’, comparable with the prairie pothole country of North America.

Wetland concerns in Russia are similar to those in the United States.  Loss of wetlands due to drainage for agriculture and water supply dams have been significant.  There is no large scale assessment of Russia’s wetlands and many systems are vulnerable to development pressures.

To help Russia manage some of its environmental issues representatives from the Russian Ministry of Economic Development, Ministry of Natural Resources and Environment, Technological Platform, Russian regional administrations, and private industry met with EPA experts in Washington, DC in 2009 to discuss development of economic mechanisms in addressing legacy waste sites in the Arctic Region. The delegation also visited United States Superfund and Brownfields sites, to observe and review innovative technologies and best practices in land remediation and destruction of hazardous wastes.

While this is not directed at wetlands, it is a start. It is reminiscent of the early days of the Clean Water Act in the 1970’s.  The focus then was water contamination.  In Russia today the major concern is hazardous waste, especially in the arctic regions.

Wetlands International has drafted a national strategy for Russia.  It includes a number of key points including:

  • Develop and implement a national wetland inventory program;
  • Protect the most important wetlands by means of designating sites of special (international, federal and regional) importance;
  • Establish a network for monitoring the status of wetlands and a system for collecting, storing and analyzing data on wetlands in the form of National Wetland Cadastre supported by relevant legislation and institutional network;
  • Develop legislation that will provide for wetland wise use and conservation throughout the country;
  • Raise the awareness in wetland functions and values among the general public and specific target groups;
  • Promote the participation of indigenous and local communities and other stakeholders in the decision-making process concerning wetland management and conservation;
  • Promote research in wetlands as a basis for management and conservation action;
  • Promote international cooperation in the field of wetland conservation and sustainable use.

Wetlands International recently published a guidebook for creating concepts for visitor centers and eco-trails in wetlands.  It is targeted at a wide audience, including those that have the intention of establishing a visitor center or a wetland center, plan to renovate an old natural history museum, design a network of walking trails, a child-friendly exhibit or a play area. This publication contains the detailed description of the steps they will go through to plan the concept development process, the practical examples and tips to avoid common mistakes.  It sounds like a great publication. Unfortunately, it is only available in Russian.   You can download it here. 

das vi danya

Марк

Winter Wetland Delineations 2014

Swamp Stomp

Volume 14, Issue 6

As I write this about two thirds of the US is covered in snow.  Here in North Carolina we are expecting another round of snow and freezing rain.   This makes any field work very difficult.  Heck, driving to the office is a challenge.  Kind of makes that whole global warming thing sound pretty good about now.

The issue is that we cannot stop work and wait for spring.  We have to get some field work done.  The problem is that we have to balance responsible science with paying the bills.  We cannot just lay everyone off when there is snow on the ground.

I have worked in the northern part of the country for many a winter.  As a result, I have developed some tips and tricks for conducting wetland delineations in less than ideal conditions.  I thought I would share a few with you while you wait for the snow plows to show up.

The first and foremost important item is do not take pictures of the snow and send it to the Corps.  You are going to have to wait until you can see bare ground.  Most Corps Districts will not even accept the reports if there are snow covered pictures.  You will need to let your clients know that there will be a follow –up site visit to finish up the field work when the snow melts.

Now, if the snow is many feet deep, you may still be stuck in the office.  First, there is a safety issue and second, there is a matter of really being able to accomplish anything when the snow is that thick.  The safety issue should not be overlooked.  In any circumstance, do not venture into the field alone.  There are just too many hazardous out there that a cell phone cannot help you with.  Hypothermia is one of the bigger hazardous you may face.  Keep an eye on each other.

If you can navigate thought the snow safely, you should be able to do a tree survey.  The trees can be identified in the winter by twigs, bark, and buds.  To be frank, this is a better way to identify them anyway.  The leaves can be misleading.  This is especially true with the red oaks.  The buds are critical to positive identification of these tricky trees.

Saplings and shrubs will also persist throughout the winter months.   Many of these are either facultative wet (FACW) or facultative up (FACU).  These can be a great help with wetland determinations.

The herbaceous species will most likely be absent.  However, there are some species that persist in the non-growing season.  These perennial species often die back to the root, but the vegetative parts remain.  Cattails and soft rush are good examples of this.  Species like skunk cabbage also die back to the bulb leaving a little leaf ball right below the ground surface in the subnivian zone.  This is the space between the snow and ground surface.

If you do encounter herbaceous species in the winter, I would suggest limiting the inventory to only perennials.  You may find remnants of annuals in the winter.  However, the problem with annuals is that they are highly variable and may be responding to a seasonal or climatic change in the hydroperiod.   This may not be typical for the site overall.  So if you are able to identify them (to species), make a note and keep an eye on the site when the snow melts.

Hydrology is going to be a tough one.  Most of the indicators will either be buried or otherwise be altered due to being frozen.  However, there are a few to keep an eye out for.

Obviously, if you see standing water you have a positive indicator of hydrology.  Be careful not to include a frozen puddle that is temporally there.  The evaporation rate is so low in the winter, that area could easily be a false positive.  Look for type “C” soil indicators as backup if you really want to call the puddle a potential wetland.  Oxidized rhizospheres would be great to find.

Last but not least are the soil indicators.  Believe it or not, most of these will persist in the non-growing season.  Even the rhizospheres will remain when the soil is frozen.

If the soil is frozen solid, you may have more of a logistical issue extracting a sample than any other issue.  There are special devices made to help you with this.  The slide hammer attachment works well on a tube sampler, but be prepared to totally destroy the sampler by the time you are done.  There are other clever devices out there.  The good old shovel will also work in frozen soil.  No need to go to the gym on that day though.

I would recommend that you take picture of the soil in its frozen state and identify any hydric indicators.  Then take the sample to the nice warm truck and see what you see when it thaws out.    Note any change in soil color as it warms.  My experience is the frozen soil is brighter in color and may give you a false negative until it melts.

The Corps may still have issues with any work done with snow cover.  Please check with your local Corps field office to see if they have any restrictions.  Even if they do, you still may be able to get a jump start on the site and be ready to finish it quickly in the spring.  For those of you way up north I think that is sometime in July.  You will have to hurry before that Labor Day snow storm.

Have a great week.  Stay warm and stay safe.

Best,

– Marc

Hydric Soil Indicators

Swamp Stomp

Volume 14, Issue 5

The most common soil type we encounter in wetlands is the “F” group of hydric soils.  These are the loamy mineral soils.  The texture needs to be a fine sand or finer.  Usually we are looking at silts and clays.

Of all of the indicators in the “F” group the two most common ones are the depleted matrix “F3” or the dark surface “F6.”  It is not unusual to find both of these in the same soil pit.  Both of these indicators are dependent upon soil color as their hydric condition test.

There are many variations of color associated with the “F” indicators.  However a basic rule of thumb is that they need to have a Munsell matrix chroma of 2 or less.  There are provisions for chromas greater than 2 found in some of the other indicators.  However for the “F3” and “F6” we need to see colors that are at least as dark as a 2.

There is still some pushback from the old time delineators on these new indicators.  For decades we used a single indicator for soil color.

  • Matrix chroma is 2 or less in mottled soils
  • Matrix chroma is 1 or less in unmottled soils

This has to occur at a depth of 10 inches or the bottom of the “A” horizon whichever is shallower.

This definition served us well but it is no longer in use.  However, when we look at the new “F” indicators we see that the old definition is buried in them (sorry for the pun).

One other oldie is the concept of mottling.  This term has been replaced with the concept of redoxomorphic features.  We now refer to dark features as redox depletions and bright features as redox concentrations.  Mottling always meant a mix of soil colors.  However, it usually was expressed when the dark features were in the matrix (dominant color) and the bright features were individual masses.  The use of the redox concentrations and redox depletions is much more descriptive and a change for the better.

Thickness of the indicator feature is also a new concept.  Many of the “F” indicators not only require a specific soil color, but also a thickness associated with it.  For example a matrix with a chroma of 2 must be at least 6 inches thick in order to count as a hydric soil feature.  To make this a bit more challenging some of these thickness requirements can be combined with other hydric soil indicators thickness   requirements to make up any missing thickness goals.  This only applies to certain indicators like the “F3” and “F6”.

The last caveat is that some of these features must occur within certain depth limits in order to count as a hydric soil feature.   You must see the feature start at a specified depth and then extend for a certain thickness.  On aspect of the “F3” requires that a depleted matrix must start in the upper 12 inches of the soil and extend for at least 6 inches.  Thickness and depth are combined.

The “F3” indicator is one of the most frequently found indicators.  It is referred to as a depleted matrix.   There is a tricky part to this indicator regarding the use of the US Army Corps Regional Supplements.  The definition of a depleted matrix is found in the glossary along with a nice graphic of what it means.  The problem is that the hydic soils section leads you to believe that the full description of the feature is found within they hydric soil indicator description.  It does not.  You need to check the glossary.

The description starts with the idea that you have a depleted matrix.  You need to know what a depleted matrix is.  This involves an analysis of the soil color and percent redox features.

A depleted matrix is:

Depleted matrix. The volume of a soil horizon or subhorizon from which iron has been removed or transformed by processes of reduction and translocation to create colors of low chroma and high value. A, E, and calcic horizons may have low chromas and high values and may therefore be mistaken for a depleted matrix. However, they are excluded from the concept of depleted matrix unless common or many, distinct or prominent redox concentrations as soft masses or pore linings are present. In some places the depleted matrix may change color upon exposure to air (reduced matrix); this phenomenon is included in the concept of depleted matrix. The following combinations of value and chroma identify a depleted matrix:

  • Matrix value of 5 or more and chroma of 1, with or without redox con- centrations occurring assoft masses and/or pore linings, or
  • Matrix value of 6 or more and chroma of 2 or 1, with or without redox concentrations occurring as soft masses and/or pore linings, or
  • Matrix value of 4 or 5 and chroma of 2, with 2 percent or more distinct or prominent redox concentrations occurring as soft masses and/or pore linings, or
  • Matrix value of 4 and chroma of 1, with 2 percent or more distinct or prominent redox concentrations occurring as soft masses and/or pore linings (USDA Natural Resources Conservation Service 2010).

Common (2 to less than 20 percent) to many (20 percent or more) redox concentrations (USDA Natural Resources Conservation Service 2002) are required in soils with matrix colors of 4/1, 4/2, and 5/2. Redox concentrations include iron and manganese masses and pore linings(Vepraskas 1992).

Once you figure that out you just need to look for depth and thickness of feature.

A layer with a depleted matrix that has 60 percent or more chroma of 2 or less and that has a minimum thickness of either:

  • 2 in. (5 cm) if the 2 in. (5 cm) is entirely within the upper 6 in. (15 cm) of the soil, or
  • 6 in. (15 cm) starting within 10 in. (25 cm) of the soil surface.

The “F6” indicator does not require a depleted matrix.  It is described as a dark surface as follows:

A layer that is at least 4 in. (10 cm) thick, is entirely within the upper 12 in. (30 cm) of the mineral soil, and has a:

  • Matrix value of 3 or less and chroma of 1 or less and 2 percent or more distinct or prominent redox concentrations occurring as soft masses or pore linings, or
  • Matrix value of 3 or less and chroma of 2 or less and 5 percent or more distinct or prominent redox concentrations occurring as soft masses or pore linings.

I should add that distinct or prominent redox features are defined by the color contrast between these features.  Please check the Regional Supplement glossary for a full description.  We also printed it on our soil bandana.

These two soil indicators can also be combined to meet the thickness requirements of either feature.  This may vary by Regional Supplement so make sure to check with the Corps for any local interpretations.

Next week we will talk about how at least one Corps district has already started to regulate upland waters of the US as described in the proposed EPA rules.

Have a great week!

– Marc