Friday, December 13, 2013

Lynnhaven River Watershed Assessment



Overview


The Lynnhaven River watershed is a subwatershed of the Chesapeake Bay.It is also one of eight subwatersheds identified in the City of Virginia Beach. It is 64 square miles, which is approximately 25% of the entire city. It consists of the Main Stem, Eastern Branch, Western Branch, and Broad and Linkhorn Bays. There are 150 miles of shoreline, and these waters drain into the Lynnhaven Bay and ultimately into the Chesapeake Bay. Common uses include recreational boating and fishing, crabbing, and ecotourism. It is home to many notable animals and plants, including the threatened Bald Eagle.





The watershed was once rural but has undergone tremendous growth. The majority of the watershed is now highly developed and largely residential. There are some areas of commercial or industrial use, and only a few sectors of undeveloped land. First Landing State Park is to the northeast and Oceana Naval Air Station is to the southeast. According to the City of Virginia Beach, Department of Public Works, the Land Use of the Lynnhaven watershed is as follows, reported as Land Use Category,  Area (acres),  and Area (%):


Single Family/Duplex 15078 37%
Town House 768 2%
Multi-family 551 4%
Commercial 1806 4%
Office 652 2%
Industrial 457 1%
Military 2393 6%
Streets 5178 13%
Public/Semi-public 2662 7%
Park 2876 7%
Agriculture-cropland 1717 4%
Agriculture-pasture 248 1%
Marsh/wetland 1711 4%
Approved f/development 6 0%
Undeveloped 3580 9%


Total Area 40683 100%






As population and development have increased over time, there has been a decrease in the natural buffers that once protected the river. This has helped to increase sedimentation, increase nutrient loading, and increase bacterial contamination.


History


It is believed that Adam Thoroughgood, an English colonist, was responsible for naming the Lynnhaven River around 1622. In 1636, he built a small brick home which still stands today and is thought to be the oldest brick home still in existence in the United States.  



Thoroughgood’s godson was Adam Keeling. Keeling was accountable for digging what is now known as Lynnhaven Inlet. This was meant to be an alternate route to enter the Chesapeake Bay.


The Keeling House is another historical home in the Lynnhaven River watershed. Others include the Francis Land House and the Lynnhaven House.


Grace Sherwood was a resident of Princess Anne County, which is now known as the City of Virginia Beach. She was accused of practicing witchcraft. Witnesses claim that she was guilty of controlling the weather, killing livestock, and destroying crops. On July 10, 1706, Sherwood had her hands and feet bound together and thrown into the Lynnhaven River. This area of the Lynnhaven watershed is now known as Witchduck Road. A memorial statue was erected in her honor in 2006.


Since the 1600’s the Lynnhaven River has been famous for their large succulent oysters, Crassostrea virginica, or the Eastern oyster.George Percy was an explorer who sailed with Captain John Smith. He has been noted to have journaled about the oysters in 1607. A colonial waste site was found in First Landing State Park that included mounds of Lynnhaven oyster shells, further proving their significance.



By the 1970’s, the stock of oysters began to diminish to the point that shellfish harvesting was no longer allowed. Increased human population, poor water quality, disease, and overfishing led to the decline.


Policy


In 1998, the Lynnhaven River was listed as impaired for bacterial contamination on Virginia’s 303(d) list of impaired water bodies. More specifically, the Virginia Water Quality Assessment Integrated Report lists Crystal Lake, Dey Cove, Milldam Creek, Linkhorn Bay, and Little Neck Creek, as being impaired for fecal coliform and enterococci. This required the development of a Total Maximum Daily Load (TMDL) for the watershed. A TMDL is a pollution cleanup plan that is issued by the Virginia Department of Environmental Quality, as required by the federal Clean Water Act. Since there are no point source dischargers into the Lynnhaven River, the bacterial contamination is attributed to human, pet, and wildlife waste. The city has worked hard to design an implementation plan to address the fecal coliform and enterococci contaminations. These parameters were often well beyond what is considered safe for shellfish harvesting and recreation. In addition, the Eastern and Western branches of the river suffer from low dissolved oxygen levels and high nutrient levels.   


In response to the river being listed as impaired, the City of Virginia Beach implemented a “NO DISCHARGE” zone for the entire Lynnhaven river. In 2007, it was only the second waterbody in Virginia to hold that title. Essentially, it banned all sewage discharges from boats, regardless of pretreatment. Violations to this policy result in a Class 1 misdemeanor, which is punishable by up to one year in jail and a $2500 fine. The city went further to work in partnership with the Virginia Department of Health and the Hampton Roads Sanitation District to provide free boat pump outs every summer. There are six marinas where boaters can go to pump their sewage and receive educational material regarding proper waste disposal and “clean boating” practices. On average, the program collects approximately 6000 gallons of sewage per summer.



The City of Virginia Beach has dedicated many other resources to protecting and improving the river. More than 11,000 septic tanks have been connected to the city sewer system. All new city construction must have no net increase in stormwater runoff. In fact, one of the most recently built city schools meets the LEED Platinum certification and has no stormwater discharge coming from it’s property. Another action that the city has taken involves a meal tax. This generates several million dollars a year to be used for the purchase of open space. Most recently, Virginia Beach worked with the public and other agencies to raise $13 million to purchase 118 acres of open space along the shore of the Lynnhaven River. The Chesapeake Bay Foundation plans to build a “living building” which will be the most sustainable building in Virginia. They will utilize green building techniques and materials, as well as be energy and water efficient.    
.
Neighborhood and Community Advocacy


Lynnhaven River Now (LRN) is a non-profit citizen group that formed in 2003 to help reduce pollution in the Lynnhaven River. They consist of over 5000 members and have been very effective in helping to improve water quality. Originally called Lynnhaven River 2007, their main objective was to improve the quality in the Lynnhaven to bring back the Eastern oyster. They set a goal of being able to eat a Lynnhaven oyster by 2007, which was the 400th anniversary of the area’s exploration by English settlers. Through leadership, partnerships, and volunteerism, the group was successful. In 2006, 7% of the river was opened to shellfish harvesting. This increased to 29% in 2007 and 31% in 2008. Today, 42% is open, although that number can vary with large storm events. There are currently 63 acres of sanctuary oyster reef and at least six commercial oyster businesses.


 
However, even with all of this success oyster populations are still at 18-20% of the historic population. To help remedy this, the city of Virginia Beach recently constructed a building for LRN to operate called the Lynnhaven Aquaculture Center. It will only be open five months out of the year yet will culture more than 10,000,000 oysters per year.



Public education and outreach is a key factor in reducing pollution in the Lynnhaven. LRN is involved in the school system and encourages children to get involved. LRN and askHRgreen.org have strived to educate the public with campaigns that include rain garden installations, Don’t Feed the Geese, Plant a Tree, and instructions on fertilizer application and alternatives. LRN and the SPCA partnered to create the Scoop the Poop campaign. It is well known and has been very successful.



Additional Partnerships


In addition to the city of Virginia Beach and LRN, there are many other organizations that are working to restore the Lynnhaven River. The National Oceanic and Atmospheric Administration, U.S. Army Corps of Engineers, the Hampton Roads Planning District Commission, Virginia Institute of Marine Sciences, Hampton Roads Sanitation District, and the Chesapeake Bay Foundation have all done work within the Lynnhaven. For instance, in September 2013, the US Army Corp of Engineers and the City of Virginia beach issued a plan to restore the tidal marshes and aquatic vegetation, re-establish a population of bay scallops, and construct reef habitat. Additionally, the Hampton Roads Planning District Commission is preparing a proposal for stormwater runoff monitoring. Likewise, the Hampton Roads Sanitation District is actively working on multiple stormwater runoff projects in Milldam Creek (part of the Eastern branch) including bacterial source tracking, and an evaluation of BMP efficiency.   



Other areas of concern
There are many people invested in the restoration of the Lynnhaven River. Data is being collected and analyzed at a rapid pace. It is imperative that the organizations communicate and share amongst each other for optimal efficiency. Furthermore, although public education is a cornerstone of the city’s plan for improving water quality in the river, more needs to be done to ensure that residents know what part they play in the process. For example, the Scoop the Poop campaign let’s people know that they should pick up after their pets, but it needs to do a better job at explaining why it is important. In a time where stormwater runoff is being treated more like a point source by state and federal regulatory agencies, picking up pet waste, managing residential stormwater runoff and using fertilizer appropriately has never been more important.The public needs to understand that they are a key factor in returning the Lynnhaven to it’s once pristine condition.

Saturday, December 7, 2013

Guidance for Wetland Restoration


Technology Evaluation

A Technical Comparison of Multi Parameter Water Quality Sondes


A multi parameter water quality sonde is an economical way of collecting real time water quality data for groundwater, industrial discharges, stormwater, and surface water monitoring.There are many options available and a lot of it depends on your intended use. However, many of the features are standard and easily comparable between vendors. Here, I intend to compare YSI, HACH, ISCO, and In-Situ multi parameter sondes.


YSI



HACH



ISCO







In-situ




Parameters:


The variety of parameters available vary depending on the sonde. However, all of the four brands of sondes offer the basic parameters of Dissolved Oxygen, pH, Conductivity, and ORP.



Dissolved Oxygen
Sensor
Range
Resolution
Accuracy
YSI ROX*
0-50mg/L
0.01mg/L
0 to 20 mg/L: ± 0.1 mg/L or 1% of reading, whichever is greater; 20 to 50 mg/L: ± 15% of reading    
HACH LDO*
0-60mg/L
0.01mg/L
±0.1mg/L @ < 8mg/L, ±0.2mg/L @ > 8mg/L, ±10% reading >20mg/L
ISCO HDO*
0-20mg/L
0.01mg/L
±0.2mg/L
In-Situ RDO*
0-8mg/L
8-20mg/L
20-50mg/L
Not found
±0.1mg/L
±0.2mg/L
±10%
* All versions of Optical Dissolved Oxygen



pH
Sensor
Range
Resolution
Accuracy
YSI
0 to 14 units
0.01 units
± 0.2 unit
HACH
0 to 14 units
0.01 units
± 0.2 unit
ISCO
0 to 14 units
0.01 units
± 0.2 unit
In-Situ
0 to 12 units
Not found
±0.1 unit


Conductivity
Sensor
Range
Resolution
Accuracy
YSI
0 to 100 mS/cm
0.001 to 0.1 mS/cm (range dependent)
± 0.5% of reading + 0.001 mS/cm
HACH
0 to 100 mS/cm
Not found
± 0.5% of reading + 0.001 mS/cm
ISCO
0 to 100 mS/cm
0.1 μS/cm (0 - 999.9)
1 μS/cm (1000 to 9,999)
10 μS/cm (10,000 to 99,990)
±1% of reading ± 0.001 mS/cm

In-Situ
Low: 0.005 to 20 mS/cm
High: .15 to 112 mS/cm

Not found
Low: ±0.5% or 0.002 mS/cm
High: ±0.5% + 0.002 mS/cm




Oxidation Reduction Potential
Sensor
Range
Resolution
Accuracy
YSI
-999 to +999 mV
0.1 mV
± 20 mV
HACH
-999 to 999 mV
1.0mV
± 20 mV
ISCO
-999 to 999 mV
1.0mV
± 20 mV
In-Situ
±1400 mV
Not found
±5 mV



It is important to note that the accuracy of each parameter is influenced by the quality of the calibration standard and adherence to calibration procedures. Specific calibration procedures can be found in each sonde’s user manual.


In addition to the four basic parameters, each sonde offers these additional parameters.


* YSI offers: Ammonia/Ammonium, Blue Green Algae, BOD, CDOM, Chloride, chlorophyll, Depth, Free Chlorine, Level, Nitrate, Oil/Hydrocarbon, Photosynthetic Active Radiation, Resistivity, Rhodamine, Salinity, Temperature, Total Dissolved Solids, Turbidity


* HACH offers: Chlorophyll, Blue Green Algae, Total Dissolved Gas, Rhodamine, Photosynthetic Active Radiation, Temperature, Turbidity, Depth, Ammonium, Nitrate, Chloride


* ISCO offers: Depth, Salinity, Total Dissolved Solids, Turbidity


* In-Situ offers: Barometric Pressure, Salinity, Total Dissolved Solids, Level/Pressure, Temperature, Turbidity, Ammonium, Nitrate, Chloride


Other details to consider include weight, power supply, maintenance, and data interface.


Detail
YSI
HACH
ISCO
In-Situ
Weight
3.4lbs
7.4lbs
5.2lbs
4.2lbs
Power Supply
4 alkaline C-cells with detachable battery cover
8 alkaline C-cells
12 VDC Supplied by connected sampler or flow meter,or USB connection to computer
2 alkaline D-cells
Maintenance
Field serviceable. Probes can be calibrated and/or changed in the field
Can be calibrated in the field but must be returned to manufacturing if you need to change or reconfigure the probes.
Field serviceable. Probes can be calibrated and/or changed in the field
Field serviceable. Probes can be calibrated and/or changed in the field





Data Interface:


Sonde
Type of data interface
Function
Pros/Cons
Picture
YSI
Handheld unit, Multi Parameter Display System
Display and record data
No need for laptop in the field, Ecowatch software, easy to use interface
*
HACH
Handheld unit, Surveyor Field Unit
Display and record data
No need for laptop in the field, waterproof, rechargeable batteries (which can be a pro or con)
*
ISCO
No handheld, must be connected to laptop or sampler
Display and record data
Eliminates the need for a handheld device, only as rugged as the laptop
*
In-Situ
Handheld unit, Rugged Reader
Display and record data
No need for laptop in the field, Rugged design, protected from dust, rain, and accidental submersion, Microsoft Windows Operating System
*



Additional Information:


Although these four brands are very comparable, YSI has recently launched it’s new EXO platform that incorporate a combination of advanced features that are unique to YSI.  “Smart probes” allow users to calibrate multiple probes during a single calibration. Furthermore, since calibrations are stored on the probe, instead of the sonde, these probes can be swapped out without having to do a recalibration. This can help to decrease errors, as well as save on the amount of calibration standard used.


“Smart ports” is another unique feature that automatically recognizes probes/sensors. It also utilizes wet-mateable connectors. This allows for sensor swaps in wet conditions.


The anti-fouling accessories and internal power also allow for continuous deployment of sondes.  The EXO2 incorporates a central port that accepts a special anti-fouling wiper that cleans all the probes that are attached to the sonde, instead of the usual individual wipers. This is a benefit because probes with individual wipers can be problematic due to the potential for the o ring on the wiper shaft to fail.  


The EXO handheld is a portable weatherproof interface for the EXO sondes that also comes with a number of unique features.  These features include GPS, temperature-compensated barometer, wet-mate wireless connector, Bluetooth communications, and 2 GB of storage.  Besides the handheld, the EXO sonde has multiple data outputs.  The sonde can be outfitted with a DCP signal output adapter, usb adapter, or via Bluetooth technology.


Water quality multiparameter sondes are a useful tool when immediate data is required. All of the sondes that are on the market are comparable in it’s abilities so the user’s needs and budget should be the deciding factor. Although other sources or manufacturers of multiparameter sondes are comparable in certain aspects, the YSI EXO sondes incorporate all of the features listed above in one package. Also, the bluetooth capability gives these new sondes added value.