Innovation

Pluris believes innovation and new engineering ideas lead to better customer service and affords better protection to the environment. Several projects highlight Pluris’s commitment to the environment as well water treatment and providing customers more direct access in managing their individual accounts online in real time. The three projects are presented in the following:

Case One – State of the Art Wastewater Treatment: A Story of Innovation and Environmental Stewardship

In 2009 Pluris purchased North Topsail Utilities, a wastewater utility serving the greater Sneads Ferry and North Topsail Beach communities in Onslow County North Carolina. At that time the utility had an aged facultative lagoon treatment system and disposed of its effluent on nearly 500 acres of spray fields. The system had been in operation for over 30 years.

Recognizing the growing need for wastewater treatment in the largely underserved surrounding area, Pluris moved quickly to expand treatment capacity recognizing that the area was in a very environmentally sensitive coastal watershed. The surrounding estuaries and waterways are home to a plethora of wildlife and very important to the quality of life of the residents.

In order to protect the environment and provide additional treatment capacity Pluris embarked on the design and construction of a state of the art membrane bioreactor (MBR) wastewater treatment system. The heart of this system are numerous membrane plates with .04 micron sized pores that filter out pathogens and other pollutants in a highly effective manner. The treatment system produces a very clean effluent with extremely low Nitrogen and Phosphorus residuals. These two pollutants are leading causes of algae blooms.

The disposal for the plant’s effluent involves an innovative high rate infiltration (HRI) design utilizing engineered material. This design allows for a very small disposal footprint and has the added benefit of further treating the effluent. The design was recognized with a 2011 Be Inspired Award for innovation in environmental projects. The treatment also impressed the White Oak River Keeper organization after representatives observed the fish tank in the treatment facility that uses the treated water in an aquarium and the Geese taking up residence in the nearby high rate infiltration pond where the water flows to after leaving the plant. Photographs of the fish tank and Geese are presented here.

Currently Pluris is completing construction of a second facility located in Hampstead, a city in Pender County, North Carolina.This new facility incorporates the same state of the art MBR treatment as the first plant in Onslow County.

Pluris’s approach to both the environment and growth is allowing for the responsible and sustainable development of communities in North Carolina.

The Onslow and Pender County Facilities plants are the first MBR plants of their size in North Carolina.The basis of design for these systems is to use state of the art technology and innovative methods of disposal to produce effluent quality at the highest achievable treatment levels. Another benefit to the Pluris MBR facilities is that the resulting treated water is perfect for reuse in community landscaping. The reuse of this water further enhances the sustainability of the community’s development by putting less stress of the potable water supplies for the area.

Case Two – Advanced Technology Used in Treatment of Wedgefield Water

 

In anticipation of the promulgation of the Disinfection By-Products (DBP’s) Rule by the EPA and the Florida Department of Environmental Protection, the utility investigated the water quality concerns that would be impacted by this new Rule. This Rule proposed the regulation of the acceptable level of DBP’s in treated potable water. Preliminary investigations indicated that the DBP levels would be exceeded. The utility immediately instituted an interim measure that prevented the formation of DBP’s through the use of an alternative disinfectant known as chloramines. However the use of chloramines can be inconsistent and sometimes problematic. Therefore, the utility undertook a study to determine a better long term solution.

A study was conducted to determine the cause of the DBP formation and possible solutions. In this study the raw groundwater was tested for DBP formation potential. It was determined that the groundwater in this area is high in natural dissolved organic material. When chlorine disinfectant is added to the groundwater for disinfection, it reacts with the organics to form Trihalomathanes. There are many types of Trihalomethanes and each of the compounds is regulated as part of the Rule and all together they are referenced as Total Trihalomethanes or TTHM’s. The addition of chlorine disinfectant into the raw water is required by Rule so the only option to reduce the TTHM’s in the water is to provide additional advanced water treatment.

Several technologies were investigated for their effectiveness in dissolved organics removal including membrane technology, air stripping, granular activated carbon filtration, and ion exchange filtration. The raw groundwater in Wedgefield is also very high in Hydrogen Sulfides. This is not a harmful compound but is considered a nuisance due to the ‘rotten egg’ smell associated with it. The high sulfide concentration in the raw water made a couple technologies infeasible. In order to process the water using membranes, air strippers would need to be used to remove the hydrogen sulfide in advance. Further, the membranes have typically a 15-20% waste rate which would have to be sent to the wastewater facility. The capacity of the wells could not provide enough water to properly feed a membrane system and the high waste rate was projected to have detrimental impacts to the wastewater treatment process and subsequent disposal. The air stripping could be efficient in removing the Sulfides, but the TTHM compounds that would get formed were not of the variety that could be effectively ‘stripped’ out of the water. This left the comparison of granular activated carbon and ion exchange systems. The granular activated carbon is effective at organics removal but has a high operations cost and would require the addition of a stripping tower to remove the sulfides. The ion exchange system was predicted to be able to remove the organics and the sulfides in a single process.

This led to the pilot testing of a technology known as magnetic ion exchange or MIEX. An illustration of the interior of a MIEX chamber along with a picture of the MIEX resin are shown below.  Raw water from water wells enter the chamber and is forced to pass through the MIEX resin. This process is very similar to hard water passing through a water softener.

MIEX testing at Wedgefield was performed for two months in a controlled setting on site so a specific resin and process rate could be determined to maximize efficiency of removal at the most cost effective rate. The pilot testing concluded that the MIEX resin effectively removed hydrogen sulfides from 2,704 parts per billion (ppb) down to 62 ppb, a 98% removal efficiency and dissolved organics up to 60%. This treatment resulted in an average TTHM level of 57.1 µg/L, which is well below the EPA Stage 1 and Stage 2 Maximum Concentration Level (MCL) of 80 µg/L. The optimum operating conditions were determined to be 18 minutes of contact time at a regeneration rate of 1 gallon per 1,000 gallons treated water. At this regeneration rate, the waste brine produced was anticipated to be on the order of 200-250 gallons per million gallons of water treated.

The design of the MIEX treatment system was initiated and construction was completed. Since the system was brought online it has consistently removed the dissolved organics from the water and prevented the excessive formation of DBP’s in the finished drinking water. It has also reliably reduced the hydrogen sulfide levels to make the water quality more aesthetically pleasing. Pluris has continued to maintain and operate the process to ensure safe, high quality drinking water to its customers.

Case Three – Advanced Metering Infrastructure and Customer Access to Real Time Monitoring

As part of Pluris’s ongoing commitment to provide high quality customer service through cost-effective, innovative systems, Pluris selected an advanced metering infrastructure (“AMI”) system for all water customers.

Pictured to the right is an illustration of an AMI meter in a meter box. The meters are manufactured by Sensus, one of the largest and most reputable companies in the United States. The meter can wirelessly communicate accurate usage data continually, reducing the potential for meter misreading. Flow information is uploaded to a secure database 24/7/365 and accessible to only Pluris customer care staff and customers. The new website features a new customer portal that will provide customers more control over their account management. AquaHawk Alerting™ will allow customers to receive potential leak alerts and access to water usage information online.

This information will be available 24 hours a day, 7 days a week and all 365 days out of the year anywhere the customer has access to the internet. So whether a customer is home or traveling, there will be real time access available.

Benefits of New Customer Portal

Receiving timely leak alerts

With the new portal you the customer can easily specify how you want to be contacted: e-mail, text or telephone. When your usage indicates high usage or a leak, you will automatically be contacted. This feature will help in early detection of possible leaks and will provide greater peace of mind when you’re away from your home.

Monitoring water usage

An additional feature will allow you the customer to see how much water you’re using and an estimate of your bill at any time during the billing cycle.

Setting Personal Threshold Alerts

Threshold alerts will allow you as the customer to input an amount of water (gallons) or a maximum dollar amount, at which point you will be notified. If your usage or your bill is trending to, or has exceeded the threshold value, you will receive a notification. Because the information is in “Real Time” you will be able to see how water use changes during hours of the day and days of the week throughout the year.

Illustrated on the following page is an example of an actual customer account. This same format will be used in Pluris’s new web portal. In this example the customer selected information including water used, and additional information including rainfall, and average outside temperature during a time period of the prior 24 hours.

Pluris remains committed to improving customer service and protecting the environment through innovative design.