TL;DR: If there’s stuff in your water that you don’t want, filter it out.
After being under a boil water advisory for a couple years (and suffering brown water in summer in the northern part of the island for a couple decades), the Prudence Island Water District’s customers are owed some sort of plan to fix the water quality problems. Wouldn’t it be nice if someone would simply tell us what to do?
Well, it turns out we have been told what to do. Engineers, the health department, product vendors, and other experts have all told us that we need to disinfect the water (with chlorine or sodium hypochlorite, like the majority of the country has done for over 100 years) and filter out the iron and manganese using greensand filtration. This plan has been around for a while, but the latest version is spelled out in a Second Amended Consent Order with the Rhode Island Department of Health.
What Is The Plan?
The consent order lays out a set of concrete steps with deadlines:
1. Apply For Project Funding by October 31, 2021
There are a couple of points to make about the funding application with the state. First, the project is at the absolute top of the priority list for the State Revolving Fund. If we apply properly, we’ll get funding. Second, if year-round residents would please complete the income survey, we might get a higher percentage of grants versus loans. Third, one of the biggest hurdles is that we must provide our financial statements as part of the loan application. This is a story for another post, but ours are not done. Nevertheless, I have been told by the bank that estimated financials are better than no financials, and have started to build detailed estimates.
2. PIWD Must Get Engineering Plans Approved by December 31, 2021
For details of the engineering studies and approvals required, please see the consent order. For a sense of what system modifications are likely, see the engineering section below.
3. After Approval, Funding, and Environmental Studies Are Complete, Build the System
When Will It Be Done? How Much Will It Cost?
If all goes well, we would hit the funding and planning milestones by the end of 2021. Environmental studies would need to be completed in 2022, followed by construction. Compliance would be achieved by the end of 2022, but the Indian Spring filtration equipment wouldn’t see much use until the busy season of 2023. Or, it could take much longer, if we drag our feet or other problems occur.
The equipment itself, a chlorinator at Army Camp and a greensand filtration setup at Indian Spring, is not overwhelmingly expensive.
The real expense may come in engineering services, site modifications, and housing the equipment. While new, the Indian Spring well building does not have a concrete floor, and may not be able to support the equipment. The site electrical plan is currently a mess. Adding a concrete building, control equipment, backwash pits, training, profit, contingency, etc., the total suggested by the engineering firm could run as high as $600,995. (Reference document not provided, it is a draft and therefore not a public record yet.)
Remember that the money we get from the infrastructure bank is likely to have a grant or “principal forgiveness” component, so district customers may not have to pay the entire amount. Taking all this into consideration, the cost to customers should still be less than $70/customer/year until the loan is paid off in 20 years. (Sadly the rates must rise more than this because the district is currently bleeding cash and has been borrowing to meet its operating expenses in violation of the charter, but more on this some other day.)
What Are The Engineering Details?
The PIWD essentially has two water sources connected directly to the distribution system. It is most economical to treat the two sources separately.
For Army Camp, which is free of iron, this means simply chlorinating. You could pretty much just switch on the existing equipment.
While we could turn on the existing equipment, we really should do a little bit more. Part of the requirement is adding the chlorine to the water, but the process also must be monitored. Army Camp has a lot of underutilized monitoring equipment already installed, such as a PLC panel and an alarm system. It just isn’t being used; isn’t plugged in! (And there’s nowhere to plug it in, no phone jacks in the woods…)
The plan for Indian Spring is a bit more involved. You could just switch on the existing chlorinator there also, but when chlorine is added to Indian Spring water, the iron and manganese are oxidized and the water turns brown.
This turns out to be a good thing, not a problem, because the oxidized iron is much easier to filter out. The suggested filter media is called “greensand”, which captures the iron and manganese oxides, which are then discarded in a “backwash” cycle.
Having been disinfected and filtered, the water is ready for distribution. Filter backwash must be sent to a pit for dewatering.
In addition to the filtration equipment, Indian Spring will need monitoring to ensure proper chlorine residual, and the site electrical must be reworked to allow the filter to stop the pumps during the backwash cycle. (Again, this is an opportunity to fix a loose end project, the current power switches are in a rotting green shed that should have been torn down.)
For more details on the filtration process recommended for Prudence Island, see the Facilities Improvement Plan, and the associated diagram.
What Happens If We Don’t Do It?
The Rhode Island Department of Health will step aside, and let the federal EPA come for us.
I’ll tell you this right now, without hesitation. Prudence Island Water District cannot stay where they are, it has to move forward. Here’s the bottom line… if the district does not move forward in the next few months, between now and the end of the year, it is a virtual certainty that USEPA is going to step in, and when they step in, it’s not going to be pleasant. … I’m telling you this as your consultant. If you guys don’t have your plan in place by the end of the year, on January 2nd the EPA is coming in. This I can guarantee.
Robert Ferrari, P.E., Northeast Water Solutions Inc.
This is certainly plausible. Communications from the EPA indicate that we’re on their radar.
Conclusion
We had a pretty good plan drawn up a decade ago, we just haven’t executed it. With the current pressure from RIDOH and the U.S. EPA, now’s the time to act. Getting this project done will require focus and undivided attention from the PIWD board.
The bad news is that the solution to Prudence Island’s water quality problems isn’t going to be cheap. The good news, however, is that once the filtration system is built, we will have the safe, clean, pleasant water, the best the island has ever had.
PIWater.org 