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MODULAR SOLUTION HELPS COSTA RICA RESORT

September 13, 2017

GLAMPING UP WASTEWATER: MODULAR SOLUTION HELPS COSTA RICA RESORT

A high end glamping resort in Costa Rica needed an advanced wastewater system, which had to be prefabricated and transported by boat, to operate in a sensitive environment.

By Allison Blodig

Building a fully environmentally friendly high-end island camping resort in Costa Rica only accessible by small boats and with no dock or centralized infrastructure is no small feat. Billed as the “ultimate glamping experience,” guests come throughout the year to the resort to enjoy the raw experience of a camping expedition in the pristine environment, while enjoying the comforts of a modern resort.

To gain approval to proceed with the resort development, Isla Chiquita owners needed a high yield advanced wastewater treatment system that would preserve the protected island in the Golf of Nicoya. Even more challenging is that the system had to be prefabricated, transported to the island by small boat, installed with no concrete, and be invisible to guests once installed.

Finally, since the property has a limited time concession of 99 years with approximately 50 years remaining, all installations at the site must be removable. In Costa Rica, all islands and beaches are now in the public domain. For existing owners, a 99-year concession right was given with strong regulations related to any changes or property improvements. These include that the concession owner is limited to maintaining existing infrastructure and can only add pre-approved removable infrastructure.

REGULATORY OVERSIGHT

Several regulating bodies were involved in the approval process for the resort. The Ministry of Environment and Energy of Costa Rica (MINAE) manages and protects the environmental resources of the country, as well as coordinating the country's energy theme. Thanks to the work carried out by MINAE, Costa Rica is today among the first places in the World Environmental Performance Index and is recognised worldwide for its efforts in conservation and sustainable development. Today over 25 percent of Costa Rica's total area is under a protection regime; whether public or private.

The Directorate of Environmental Quality Management (DIGECA), part of the MINAE, oversees pollution prevention issues and promotes environmental management (through voluntary mechanisms and regulations) to ensure that public and private activities, work, and projects are framed with a sustainable development vision.

The Ministry of Health is also involved with regulating these systems to protect the public health, approving the location, construction and operation of all wastewater treatment systems in Costa Rica. The Isla Chiquita system was required to meet the Decrete 39887-S-MINAE for construction; which also dictates a minimum of 50 mg/l for the BOD and TSS. Additionally, the treated effluent was required to be <30 mg/l FOG and <150 mg/l BQD. The system cannot exceed 38 dB for environmental noise and no septic odors can be noticeable.

ENVIRONMENTAL AND LOGISTICAL CHALLENGES

The modular wastewater treatment system design by Bionest Costa Rica, has a design flow of nine m3/day. Because Installation of the systems is between the tents and near the restaurant, any system components needed to be invisible to resort guests. Additionally, due to the location, the system had to operate silently and with no presence of odor anywhere in the area.

Assembled tanks and system components needed to be placed on site and installed using only man power. Also, the design had to accommodate the variation in flows from an average of 70 percent during the high season to 40 to 50 percent over the low season.

The use of regular septic tanks for this site are prohibited by environmental regulations so the design features two modular systems that include a combination of Bionest fixed media bioreactor technology installed inside four Infiltrator IM-1060 plastic tanks and four IM-1060 settling tanks. No concrete was included per environmental regulation and the system components were delivered by small boat, hand carried to the site, and assembled. Due to the limited time concession for the island project and the island location delivery challenges, concrete tanks were not an option.

The Bionest technology is certified to NSF (National Sanitation Foundation) Standards 40 & 245 to not exceed maximum averages of 25 mg/L of cBOD, 30 mg/L of TSS and a 50% Total Nitrogen removal.  It also has certification under BNQ (Bureau de normalisation du Québec) Class III and V for more stringent average effluent criteria of 15 mg/L of cBOD, 15 mg/L of TSS as well as disinfection of less than 200 CFU (colony forming units) of fecal coliform. The product also carries the CE mark which demonstrates it has met European product directives. Canadian regulations do not apply in Costa Rica; however, Bionest decided to design the Isla Chiquita system to comply with the stricter Canadian regulations. 

TECHNOLOGY SELECTED

The technology uses fixed media in the treatment process which is more robust than other types of technologies. The reason for this improved performance is that the media provides a place for bacteria, that treat the wastewater, to attach, live and grow.  This allows for layers of bacteria and higher life forms to develop which are more resilient to toxic events and can handle a higher strength wastewater.

At Isla Chiquita, the treated effluent quality after disinfection is Reuse Type 1-Irrigation Drip System and therefore a drip irrigation system was designed to maintain the surrounding gardens and green areas throughout the resort with no environmental impact. Additionally, the system does not require a full-time operator making it low maintenance and features minimal energy consumption. Among the secondary or tertiary technologies available in the market, the versatile combination of the Bionest Technology and the Infiltrator plastic tanks provided the ideal solution for this remote, environmentally sensitive site.

INSTALLATION PROCESS

The installation is composed of two 4.5 m3/day systems installed in parallel. All the wastewater produced by the facilities (black, grey, and high strength after a proper grease trap) are conducted by PVC pipes to the two settling or septic tanks. The tanks are equipped with an effluent filter on the outlet side. Separation of solids and liquids is completed in the tanks along with anaerobic biological treatment of the effluent.

Following the settling tanks the effluent travels to the bioreactors equipped with Bionest media, fine bubble diffusers, and a recirculation system for tertiary treatment. Finally, the treated water travels through a disinfection unit before use in the resort’s underground drip irrigation system.

"It was extremely challenging to design a wastewater treatment system that would meet all of the regulatory requirements and logistical difficulties of the Isla Chiquita project,” says Eduardo Berrocal from Bionest Technologies Inc. “The system we ultimately installed provides the utmost protection of the sensitive island environment and does so in harmony with the surroundings and beautiful landscaping.”

The resort opened in spring 2017 and the wastewater treatment system is functioning well with no visual, noise, or odor contamination to distract guests. 

Author's note: Allison Blodig is the senior regulatory specialist at Infiltrator Water Technologies.

http://www.waterworld.com/articles/wwi/2017/09/glamping-up-wastewater-modular-solution-helps-costa-rica-resort.html

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