Committee considers local science solutions


(1) More changes at the Fresh Pond part of the Delaware Seashore State Park, as transportation engineers prepare to mitigate wetland impacts associated with the Indian River Inlet Bridge.
(2) More support for a tidal pump to clean up South Bethany’s lagoons.

(3) More ammunition in the Department of Natural Resources and Environmental Control’s (DNREC’s) fight to clean up the Inland Bays watershed.

All these, in no particular order, plus nifty gadgets, at the Nov. 4 meeting of the Center for the Inland Bays (CIB) Scientific & Technical Advisory Committee (STAC).

The University of Delaware’s Graduate College of Marine Studies (CMS) once again played host — scientists and the laity gathered round to learn more.

Justin Reel’s home company, RK&K Engineers, has been working with the Delaware Department of Transportation (DelDOT) on a total environmental mitigation package.

He talked about wetland mitigation, the net sum of which is slated to take place at two Fresh Pond sites, one north and one south.

“We’ll put in quite a bit of roadway,” Reel pointed out — nearly 9,000 linear feet of approaches and nearly 10,000 linear feet of park access roads.

Add soil and some random park components (parking lots, campsites) and DelDOT wound up owing a 4-acre bill to the Army Corps of Engineers and another nearly 3 acres to DNREC.

Where to mitigate these impacts?

“We were caught between a rock and a hard place, because we had to avoid the wetlands to the greatest extent possible – but we also had a very sensitive uplands dune system that we wanted to avoid,” Reel said.

They looked at 13 possible mitigation sites, arching westward along both banks of the Indian River Bay. However, in the end, every single one of them had a “fatal flaw,” Reel said — other than (1) Fresh Pond north and (2) Fresh Pond south.

Fresh Pond north borders the actual bay. Reel said they’d discovered an archaeological site there, and so will need to avoid disturbing that area. Even so, they’ll be able to realize nearly 3 acres of wetland creation, and another 3 acres of wetland “enhancement.”

In essence, these activities involve the gentle mechanical grading of land, downward, to encourage the wetlands’ trademark spartina alterniflora (smooth cordgrass, also known as saltmarsh cordgrass).

The rest of the grading and cordgrass encouragement will take place at Fresh Pond south. DelDOT representatives alluded to a tragic occurrence at this site, and Delaware Seashore State Parks Director Ken Farrall confirmed their comments — an elderly gentleman had drowned in one of the ponds there, six or seven years ago.

According to Farrall, the ponds (actually old borrow pits) were very deep, and steep-walled. Although he was unclear regarding the exact details surrounding the accident, he suggested the victim had gone swimming on a particularly hot day and found himself unable to climb back out.

DNREC representatives had asked DelDOT to combine wetland mitigation with a rectification of this potentially hazardous location, Farrall confirmed.

Reel said they planned to blend the eastern pond (or borrow pit) into the adjacent salt and brackish marshes, converting everything into a full spartina alterniflora marsh. The northern borders of the western pond (headed toward the Fresh Pond parking area on Hickman Road) would also be converted to wetland.

Reel also covered issues related to the diamondback terrapin (according to some DNREC officials, once a local delicacy). DNREC, and more recently DelDOT, have installed “turtle fences” to keep the diamondback terrapins from attempting to cross Route 1.

The turtles are driven by instinct to lay their eggs near high ground, Reel pointed out. The fencing had significantly reduced roadway mortality, but given even the smallest gap, they continue to struggle toward the dunes east of the highway.

Now, Reel said, DelDOT was planning to incorporate three “terrapin eco-passages,” as a pilot program. The fences would funnel turtles toward concrete culverts, linking the marshes to the ocean beaches.

He also noted the creation of new turtle habitat at a site north of the inlet (Haven Road), where the Delaware Corporate Wetlands Restoration Partnership (DCWRP) heaped truckloads of clean, fine sand in an area Delaware Seashore State Parks planned to close anyway.

Finally, Reel touched on recent action to sterilize a stand of Japanese black pine (an invasive species) north of the inlet, and plans to pump up an artificial reef roughly 5 miles east of the inlet, using materials from the old inlet bridge (scheduled for demolition).

South Bethany resident Lloyd Hughes has spent the last several years volunteering his time in data collection, as supporting research for his tidal pump idea but also for the CIB’s more general benefit.

The problem — South Bethany’s dead-end canals are largely stagnant, and therefore dirty. Fish kills haven’t been much of a problem in South Bethany, because there aren’t many fish. However, Hughes said they had problems with certain phytoplankton associated with “harmful algal blooms,” or HABs (further associated with red tides).

Hughes said he’d heard things were much worse in the days before central sewer came to South Bethany. However, he suggested there were still some local offenders, citing onsite septic systems at one manufactured home community near Dirickson Creek (south side of Little Assawoman Bay).

Whenever mid-June through mid-September temperatures combined with persistent southeast to southwest winds, water quality took a dive, he said.

Hughes suggestion has been to bore two pipes under Route 1, creating a new gateway for cleaner (although slightly- to somewhat-saltier) ocean water. Basing the tidal pump system primarily on tide height differentials, he recently commissioned the Entrix Corporation for computer modeling.

As it stands, the water does a lot of sloshing back and forth — there might be a very slight southward trend, he said, but the waters have a long way to go (Ocean City Inlet) before they wash out to sea.

Entrix’s Mike Fichera ran the model at the Nov. 4 STAC. Ocean water comes in through a pipe extending 1,600 feet from the shore (buried, near shore), at North Sixth Street. That larger pipe would disperse ocean water through smaller pipes, to most of the canals.

When the tides switch, canal water drains out into the oceans, back through the pipe at North Sixth and also through a second pipe, near the town’s south border (fitted with a one-way flapper valve).

Fichera’s computer model hypothetically dumped a bunch of red dye in the canals, and then waited to see how long it would take to dissipate. Using current conditions, he said he’d shut the program down after three months. Other than the sloshing back and forth with the tides, nothing much was happening.

With Hughes’ Tidal Pump, the hypothetical dye still sloshed back and forth – but it also dissipated southward. Most of the polluted, stagnant water flushed out of the dead-end lagoons within 30 days.

Fichera went so far as to suggest the system could ultimately improve water quality in Little Assawoman Bay itself.

Some of the STAC members in attendance voiced a desire for further study, in particular regarding how the system would work in extreme conditions (flooding concerns).

Hughes has admitted the system won’t be cheap — his 2003 binder on the project set the price tag at $3 million. He expected the main expense would come in burying the 1,600-foot section of pipe, between the beachface and where it would resurface beyond the breakers.

CMS Professor William Ullman made a presentation on his own behalf and on behalf his colleague, A. Scott Andres (Delaware Geological Survey).

For Andres, he talked about nutrient transport in southern Delaware streams, how successful they’d been in estimating nutrient loading, and where they might need to develop better strategies.

These issues are very closely related to DNREC’s pending pollution control strategy (PCS) regulations. The PCS aims to improve water quality by reducing nitrogen and phosphorus loading — that is, the total maximum daily loads (TMDLs).

Too much nitrogen and phosphorus means eutrophication (over-enrichment), and that leads to excessive algae growth. Then the algae dies, and stinks, and decomposition uses up all the dissolved oxygen, killing the fish.

Currently, DNREC is pushing for adoption of the Inland Bays PCS, which encompasses the Rehoboth, Indian River and Little Assawoman bays. There are other PCS documents in queue behind it, for other watersheds.

Underflow — “water flowing through the sandbox, missing the gauges” — remained an issue, Ullman pointed out, as did the contribution from geologic materials (such as phosphorus-rich deposits).

They needed to concentrate on measuring flow accurately and frequently, which meant a need for more monitoring stations, he said. And most importantly, they needed to gather data at low base flow (drought conditions) and during and after storm events.

Ullman said a lot of the intermediate samples weren’t proving all that useful.

He and DNREC’s Jennifer Volk ran a slide show of a recent monitoring station installation at Millsboro Pond.

This state-of-the-art piece of equipment, the “Greenspan Aqualab,” weighs approximately 600 pounds. Total costs for the station, plus a platform next to the bridge, and a shed, and installation (via crane, through the roof) cost nearly $40,000, he said.

Ullman said they’d also created what might have been one of the worst traffic jams on Route 24 in recent years (although the crane was in and out within an hour).

The unit rides just below the waterline, above the weir (spillway), and measures acidity, conductivity, salinity, turbidity, concentrations for various forms of nitrates and phosphates.

It’s self-calibrating, automatically rinses its sensor probes in boric acid after each use, and best of all — you can call it on the telephone and tell it to run a sample.

University of Delaware’s Jim Glancey detailed features of a much less expensive piece of water monitoring equipment — closer to the $4,000 range.

Glancey’s machine measured weather data, temperature versus depth, salinity versus depth and dissolved oxygen versus depth, with the sensors mounted at the end of a small winch.

Ullman and Volk’s station at Millsboro Pond was hard-wired — this unit was powered by solar panels. However, just like the primo model, Glancey’s transmitted data via modem, and he said he just posted a Web page from there.

The next STAC meeting is slated for Jan. 13 — for more information, visit their Web site, at www.inlandbays.org.