By Kevin R. Bodge, PhD and Erik J. Olsen, PE
Introduction. It was recognized that gaining access to the Maple Leaf would require excavation and subsequent disposal of the overlying riverbed sediments. Such activities constitute a potential disturbance of the local waters and the state-owned bottom lands of the
St. Johns River, and accordingly require federal and state permits and easements.
The firm of Olsen Associates, Inc., under took the tasks of obtaining the permits required for the Maple Leaf exploration from environmental and land-use perspectives. The formal permitting process required about 12 to 17 months and primarily included one Federal and two State agencies. The environmental permits for the Maple Leaf Project are unique in that they allow the open-water disposal of hydraulically excavated material. This is thought to be an almost unprecedented action in the modern history of permitting in Florida for such activities.
Permitting of the salvage aspects of the project was undertaken simultaneously and is discussed in the previous chapter.
The environmental permitting of the Maple Leaf involved the U.S. Army Corps of Engineers (COE) and its sister agencies which issue a Dredge & Fill Permit under Section 404 of the Clean Water Act and Section 10 of the Rivers and Harbors Act of 1899; Florida Department of Environmental Regulation (DER) which issues a Water Quality Certificate related to the dredge- and-fill activities under Chapter 403, Florida Statutes, and Florida Administrative Code, Section 17-4;
· Florida Department of Natural Resources (DNR), Division of State Lands which issues a Management Agreement pursuant to Chapter 253, Florida Statutes for the activities upon state-owned bottom lands (that is, the bed of the St. Johns River).
· Additionally, liaison with the U.S. Coast Guard (USCG) and the Florida Marine Patrol (FMP) was required to ensure that the project conformed with federal and state requirements for safe navigation.
Prior to 1984, salvage or exploration involving Florida's state lands essentially
required only the consent of the Florida Department of State, Division of Historic
Resources (DHR). In 1984, the Florida Legislature amended Florida Statute 253.77,
which requires that any excavation of state sovereignty submerged lands be consented or
permitted by the Trustees of the Internal Improvement Trust Fund. The consent is basically
administered by the Division of State Lands of the Department of Natural Resources. The amendment of the statute was also interpreted by the Corps of Engineers and DER to imply that shipwreck salvage fell under their definitions of dredge- and-fill activities, which require
permitting. The consent of DHR is normally still necessary for salvage and exploration;
however, the environmental and some state sovereignty aspects of the activities are now
scrutinized by the COE, DER, and State Lands.
The sequence of the actions of these agencies requires that COE issue its permit only after DER issues. Issuance of a contract from DHR for salvage is considered concurrently with the COE and DER permitting process. State Lands may consent after the COE and DER issue their permits (or, their Intent-to Issue) and after receiving a copy of the salvage agreement with DHR. Liaison with USCG and FMP can be conducted simultaneously with the permitting process.
Advance consultation with the state agencies ultimately responsible for permitting began in December 1985. Formal (joint) applications to the COE and DER were made a year later, in December 1986. (The amendments to Florida Statute 253.77 became effective in June 1986.) The environmental permitting agent for the St. Johns Archaeological Expedition, Inc., was the firm of Olsen Associates, Inc., which specializes in the design and permitting of coastal and marine works, including dredge-and-fill projects. The application called for the excavation of up to 660 cubic yards [cy] of silt (that is, an area 185 feet long by 24 feet wide by four feet deep) over a 24-feet month period. The excavated material would be released at depth (20- feet maximum) or blown away by jet pump. In January 1987, the DER requested additional hydrographic data to supplement the application. The request included current velocities, sediment characteristics, predicted dredge discharge rates, and dispersal estimates of the resultant plume at the project site. In response, ebb-and-flood velocities through the water column were measured at the site every 30 minutes for a seven-hour period on April 25, 1987. The depth-averaged velocities, with maxima of I. I fps (feet per second) flood and 1.4 fps ebb, were best-fit to the expression:
u a cos wt + b (7.1) where a and b are the tidal and riverine flow components, respectively, w equals 0.49 rad/ hr (tidal frequency) and t equals time. This equation would be utilized in the plume dispersal model, described below. For the measured data, a equals 1.35 fps and b equals 0.044 fps. Bottom sediments were measured to contain 650 mg/l chloride and 1.35 mg/l total phosphate with pH equaling 7.1. Grain size analysis indicated 25 percent sand, 66.5 percent silt, and 8.4 percent clay. Of the sand fraction, two- thirds was greater than 1 .4 mm diameter and consisted of whole and broken shell. The normal discharge rate was computed at about 5 cy per day with maximum daily discharge of 25 cy. This assumed the use of a 320 gpm pump with 10 percent solids, 50 percent efficiency, and four hours of operation per day. Maximum discharge concentration was similarly estimated at 120 g/l. The lateral extent of the sediment plume which was expected to result from the open water discharge was predicted from the use of the diffusion equation under the assumptions of vertically averaged flow and sediment concentration, slowly varying current (equation 7.1), and a uniform diffusion coefficient of 0.25ft. 2/Sec. From this approach, it was determined that local concentrations would be less than 10 percent of the discharge concentration within 125 feet (38 m) of the project site. Even for the worst case simulated condition, where the discharge took place during slack tide, cumulative plume concentrations at the site would be less than three times the discharge concentration and would reduce to the discharge concentration within about 35 feet (1Gm). The maximum plume distance for the one percent concentration isopeth was predicted to be 13,000 feet (3960 in). These responses and analyses were submitted to the DER in July 1987. Within a month, the agency indicated that it had no objection to permitting the proposed open-water disposal from a hydrographic standpoint. Likewise, the Corps' "sister" agencies (the Environmental Protection Agency, the National Marine Fisheries, and the U.S. Fish and Wildlife Service) filed no objections to the permit application.
In August and September 1987, however, three objections to the project from a resident near the site and an objection from the City of Jacksonville's Department of Health, Welfare, and Bio-Environmental Services were filed with the COE and the DER. Objections stemmed from the perceptions of these parties about turbidity, navigation, and aesthetic impacts of the proposed activity, as well as the applicant's financial responsibility and the historic value of the project. In addressing these concerns, it was noted that similar projects permitted without city objection involved the release of greater amounts of fine sediment. For example, dredging of a yacht basin in the St. Johns River in 1987 was estimated to release 2.5 cy/hr or 20 cy/day; over a 45-day period due to the silt content of the bottom material, which was loaded into a hopper barge at the site. The total discharge, 900 cy, exceeded the Maple Leafs minimum expected discharge of 15 cy by 6000 percent, and the maximum permitted discharge by 660 cy by 136 percent. The objections of the residents and the City were eventually over come. The DER released its Intent-to-Issue on October 22, 1987, for the excavation of up to 660 cy over a 12 to 60-month period, using a four- inch diameter, diver-operated venturi-type suction dredge with discharge at depth. Permit conditions included the measurement of turbidity 150 feet updrift (background) and 150 feet downdrift (plume) at mid-depth once every four hours of excavation. Turbidity measurements exceeding 29 NTU above back ground would result in the use of a modified dredge/discharge procedure. However, in early November, the DER proposed that a stipulation be added that all dredge disposal be to an upland site. The Applicant took strong exception to this requirement on the grounds that it was neither warranted or cost effective. After some negotiation, monitoring requirements were modified to include measurements at three depths laterally from the site (back ground) and downdrift at three depths (plume) within 100 m of the project site. The upland disposal proposal was subsequently rescinded. DER issued its five-year permit on December 22, 1987, subject to the modified monitoring requirements (DER 161286232; expires December 22, 1992). Similarly, the Corps issued a five-year permit on February 10, 1988 (USACE 871PP-20563, expiring February 10, 1993). A Sovereignty Submerged Lands Use Agreement was executed by the DNR Division of State Lands for a five-year period beginning in May 1988, (DNR Use Agreement No. U-0 176, expires May 19, 1993). Considerable delay and frustration in the State Lands aspect of the process resulted from the division's uncertainties as to the proper form of easement for the project, and its concerns that DHR had no authority to enter into a salvage contract. Application for an Approval of Marine Event was submitted to the local Coast Guard office in June 1987. The application required disclosure of a lighting plan, licensed radio frequencies, vessel descriptions, diver operations and so forth. The USCG Commanding Officer at Jacksonville responded to the COE in Au gust 1987, requesting that the permits require that USCG be notified before each salvage operation begins.
Operations to Date.
As of November 1992, it is estimated that substantially less than the originally permitted cubic yards have been excavated from the site. That is, only limited deck mapping and access to the hull's aft cargo area has been undertaken to date. In no event did the local turbidity resulting from the activity exceed or approach 29 NTU above ambient levels. Requests to renew the DER and COE permits and the State Lands Use Agreement were submitted to the agencies in November 1992.