At 186 miles (300 kilometers) long, Lake Powell originated in 1963 when the Glen Canyon Dam began holding back the Colorado River. Midway between the Canyon-lands and Grand Canyon national parks, Glen Canyon National Recreation Area provides natural and human-made ecosystems. The interaction and effects of these resources are the subject of study and controversy.
The recreation area is managed as a unit of the U.S. National Park Service with most visitor services provided by the concessionaire Lake Powell Resorts and Marinas. This agency is a business unit of the ARAMARK Sports & Entertainment Services in Page, Ariz., and a division of ARAMARK Corp., based in Philadelphia, Penn.
Lake Powell services include marinas, motels, restaurants and gift shops supporting various recreational opportunities. About 2.7 million visitors annually enjoy boating, recreational vehicle use, hiking, camping and sightseeing in this area. However, visitor activities have environmental impacts that can harm the land and water.
The National Park Service aims to preserve, protect and maintain the recreation area’s resources and ARAMARK helps with these obligations. A recently met long-term goal was to obtain federal designation as a No Discharge Zone to prohibit sewage discharge from vessels into Lake Powell.
An average seven to eight closures annually occurred at the recreation area when the National Park Service’s water quality monitoring program found fecal choliform bacteria in boat-accessible canyons or high-use beach areas. Fecal choliform bacteria indicates that pathogens associated with human waste are present.
A No Discharge Zone designation could not be made until Regions 8 and 9 of the Environmental Protection Agency (EPA) determined that facilities were available for safe, sanitary removal and treatment of sewage from all vessels on Lake Powell. EPA applications for prohibition had to come from the states of Utah and Arizona.
The National Park Service and ARAMARK developed and implemented a waste removal method to provide and service facilities to span the 35- to 45-mile (56- to 72-kilo-meter) gaps between the five marinas on Lake Powell. These marinas provide 61 sewage pumpouts at the most congested areas where land-based sewage treatment facilities are available. Eight floating mid-channel remote pumpout facilities were needed.
 This portable toilet dump sink decreases the likelihood that a boater will pump sewage into the lake between marina stops. |
ARAMARK and the National Park Service agreed to fund the facilities through ARAMARK’s special accounts program. These funds accrue based on a percentage of concessionaire revenue and are reserved for projects that benefit the National Park Service, ARAMARK and the public.
The National Park Service designed a building for each dock to include two unisex restrooms and a portable toilet dump station. Design considerations for handicap accessibility met Americans with Disabilities Act (ADA) guidelines.
A hand operated diaphragm pump now allows boaters to pump their vessel’s sewage into a holding tank at one of the docks without traveling long distances to a major marina. This convenience decreases the likelihood that a boater will
pump sewage into the water.
ARAMARK designed and built the docks, tanks and structures for the floating facilities. Each includes a 4,000- gallon (15,141-liter) double-wall sewage holding tank. The design provides the level of release protection normally required for petroleum oil tankers. The holding tanks are suspended in the water beneath each dock between normal flotation tanks. One design concern involved the freeboard dock height above the lake surface when a holding tank is full or empty. Calculating the weights, volumes and flotation capacity provided an optimum design. The docks, tanks, buildings and major structures are made of steel and are recyclable. Decking is composed of a maintenance-free composite fiberglass sheet offering a sustainable design that lasts for decades. Dock edging material consists of heavy recycled plastic lumber — also maintenance-free and recyclable. Steel tanks and dock structures are coated with self-priming high-performance epoxy rated for full immersion and EPA-approved for potable water use.
 Batteries power a diaphragm pump that drafts lake water for flushing the stainless steel toilets. |
A solar battery charging system provides
renewable energy to keep a bank of 12-volt DC lead-acid, deep-cycle, maintenance-free
batteries charged. These spill-proof batteries power a diaphragm pump that
drafts lake water for flushing the stainless steel toilets and for the portable
toilet dump station washdown and rinse hose.
The battery bank also provides 12-volt lighting inside
the restrooms. A door switch automatically turns the light on and off as the
restrooms are used. To comply with navigation rules, a US Coast Guard-approved
360-degree white anchor light turns on at night via a photocell.
The 4,000-gallon (15,141-liter) capacity holding
tank built into each pumpout dock provides overfill protection to prevent
sewage discharge from the facility. A float closes a normally-open switch
at 80 percent of tank capacity. The pumpout docks feature a low maintenance,
sustainable design anchoring system to accommodate reservoir water level fluctuations.
Lake Powell’s annual water height varies up to 40 vertical feet. Requiring
no winches, the two main anchor cables are attached to anchor blocks on the
lake bottom. From the anchor blocks, opposing anchor cables run over sheave
blocks beneath the dock to a common spring block that keeps constant tension
on the system and allows for variable water depth. The spring block weight
provides secure anchoring but has no adverse effect on dock flotation levels.
Two double-hull steel tank barges, one at the north
and one at south end of the lake, service the eight floating pumpout facilities.
Each barge has a 10,000-gallon (37,853-liter) tank within its hull. A floating
pumpout facility holding tank’s contents are transferred to the tank
barge using a deck-mounted gasoline engine driven diaphragm pump.
A steel push boat designed and built by ARAMARK provides
power to transport the tank barges. The push boat main propulsion engines
are diesel-powered John Deere 175 horsepower featuring PTO-driven hydraulic
pumps for a single-cylinder steering system operated by a jog lever.
When a service run is complete, the waste is
taken to a marina with pumpouts that discharge to an approved
sewage treatment facility.
The first two remote floating pumpout facilities
began operating in 1997 and the other six in 1998. Since then, no closures
have occurred on Lake Powell. An average 300,000 gallons (1,135,590
liters) of sewage have been transported annually from the pumpout facilities
using push boats and barges.
In September 2000, the EPA finalized its determination
that adequate sewage handling facilities existed on Lake Powell to designate
it as a No Discharge Zone. This move
represents a milestone in protecting the resources of Glen Canyon National
Recreation Area.
Future plans include adding two more floating pump-out
facilities for a total of 10. The existing two small
pumpout barges will be replaced for the
2001 season with one 30,000-gallon
(113,559-liter) capacity barge. The two smaller
barges will be converted to restroom facilities to service
public docks at two marinas during 2001 and provide a mobile boat pumpout
service.
The floating pumpout
facilities on Lake Powell have successfully
kept water quality pristine and have proven that
partnerships among government and private agencies can reap rich rewards.
R
Mark Suttie is director of environmental
programs for Lake Powell
Resorts & Marinas, 2040 E. Frontage Road, P.O. Box 1926, Page, AZ
86040, USA; 520-645-6053, fax 520-645-6107, suttie-mark@aramark.com.