QCBFD Water System Update June 2020 Take Home Message RIDOH - - PowerPoint PPT Presentation
QCBFD Water System Update June 2020 Take Home Message RIDOH Absolute Mandate April - May 2020 1. Immediate chemical (chlorine) disinfection 4-log compliant well #1 a. This is an unprecedented concession by RIDOH 2. Submit plans for
RIDOH Absolute Mandate April - May 2020
1. Immediate chemical (chlorine) disinfection 4-log compliant well #1
a. This is an unprecedented concession by RIDOH
2. Submit plans for Pumphouse expansion to DEM/CRMC by June 2021 3. Iron amelioration or third low-iron source well decision by July 2021 4. Terms of execution under ongoing negotiation 5. Chemical 4-log disinfection is NOT negotiable
Once Well #1 achieves 4-log disinfection
1. Boil water advisory will be lifted
○ Unlikely this will happen before September
2. Well #1 will be the ONLY well providing daily water 3. Community MUST conserve water during peak season water demands
○ Months of July and August especially July 4th weekend
4. If Well #2 is required for supplementation or redundant backup
○ Boil Water Advisory will be reinstituted
1. E Coli has NEVER been isolated from the distribution system and has been cleared from Well #2 since October 2019 2. Well #1 sampling continues to show Total Coliform
a. Basis for ongoing Boil Water Advisory (BWA)
3. To date, even though we remain on a BWA, water sampling has NEVER revealed E Coli in the distribution system 4. Sampling has NOT revealed ANY bacteria within our distribution system since November 2019 5. Simply put, the water coming out of your faucet has been bacteria free since November 2019
1. Committed to providing the community with safe drinking water 2. Immediately removed Well #2 (E Coli) from the water system 3. Engaged three Professional Engineering Firms
a. Northeast Water Systems (Essex, RI) i. Water System Operator b. C&E Engineering (Woonsocket, RI) c. WSP Engineering (Madison, CT)
4. With our consultants we have been able to negotiate a path forward with RIDOH
1. Given shallow ground water source wells there is significant potential for future water quality, not water quantity, issues 2. 4-log non-chemical disinfection, i.e. UV system
a. RIDOH will NOT allow nonchemical 4-log disinfection
3. Chemical 4-log disinfection system for our water source
a. Significant technical issues i. Chlorine Disinfection Byproducts (CDP) ii. High iron in Well #2 iii. Constrained well field
4. PWC is committed to a system design which will protect our water quality for years to come
PW Committee options for CBP and Iron amelioration
1. CBP reduction 185 nm UV pretreatment
a. Reduces Total Organic Compounds for CBP control
2. Media Filtration
a. Will only address elevated iron levels i. Looking at year over year maintenance and operating costs ii. Researching parasitic water loss
3. Membrane Filtration
a. Manufacturer needs to determine if system will work for our situation b. Will address several water quality issues:Iron, Nitrates, Organic Compounds, turbidity and bacteria i. Looking at year over year maintenance and operating costs ii. Researching parasitic water loss
4. Sourcing a third well, low-iron, in present wellfield
a. DEM/CRMC and RIDOH permitting. No assurance iron levels will remain low
The Central Beach water system is licensed by RIDOH as a Public Water System #RI1647512 to operate a Community public water system; we are subject to and must comply with various regulatory requirements, including: A. Rhode Island’s Rules and Regulations Pertaining to Public Drinking Water [216-RICR-50-05-1] B. Federal Government’s Safe Drinking Water Act C. Federal EPA Total Coliform Rule D. Federal EPA Ground Water Source Rule
published in 1989 and became effective in 1990. The rule set both a health goal (Maximum Contaminant Level Goal (MCLG)) and legal limits (Maximum Contaminant Levels (MCLs)) for the presence of total coliforms in drinking water.
in which researchers found very low levels of coliforms. The MCL levels are based on the positive sample tests for total coliforms (monthly MCL), or for total coliforms and Escherichia coli (E. coli) or fecal coliforms (acute MCL).
distribution system and monitoring for the presence of microbial contamination.
The EPA issued the Ground Water Rule (GWR) to improve drinking water quality and provide protection from disease-causing microorganisms. Water systems that have ground water sources may be susceptible to fecal contamination. In many cases, fecal contamination can contain disease causing pathogens. The purpose
drinking water. The GWR applies to public water systems that use ground water as a source of drinking water. The rule also applies to any system that delivers surface and ground water to consumers where the ground water is added to the distribution system without treatment. The GWR was published in the Federal Register on November 8, 2006.
The TCR and GWR require we obtain monthly samples of both wells and the distribution system (usually taken at a kitchen tap from a residence)
○ Sample is repeated
○ Sample repeated ○ 2 further samples (one upstream and one downstream also obtained) for a total of 3
○ + distribution samples high risk of triggering an assessment
1. Early & mid 1920s: Howard Thorp sell lots located in Quonochontaug Central Beach (QCB), Charlestown, RI. Deeds contain provisions for access to water lines to the properties.: 2. 1 930: QCB vote to form Quonochontaug Central Beach Fire District (QCBFD). The enabling legislation includes provisions among other things the right to “construct and maintain its own water works, mains, and
At this time the water system was seasonal 3. 1948: QCBFD agrees to acquire the water system properties from Thorp. At this time the system’s well and pump house were located in the area that is now the playground and ball field 4. 1948-9: Well #1 was developed (created) and a new pump house constructed in the current wellfield north of Seabreeze Avenue 5. 1965: Well #2 was added in the same area approximately 100’ west of Well #1
1. 1982: The seasonal distribution system was converted to a year round system; PVC pipe was laid for the distribution system 2. 1990: Two hydropneumatic storage tanks added to allow for water storage 1775 gallons each (1000 gallons usable storage per tank) 3. 1997: Pumphouse enlarged to allow for calcite pH adjustment system 4. 1999: Hydropneumatic tanks relined 5. 2008-2010: Major water system upgrade performed a. 8000 gallon storage tank installed with UV lamp to recirculate and sterilize water in storage tank b. Control panel for seamless well pump duty cycle control and improved online remote monitoring c. Upgraded water system pH and corrosion control treatment
Well Field 1 Well Field 2
Well 1 Well 2
Pumphouse
Storage Tank 8000 Gallons
Distribution
Well 1 and Well 2 are both shallow Groundwater Source wells
Pumphouse
Storage Tank
8000 Gallons
Feed from Well 1 Feed from Well 2 Particulate Filter pH adjuster and corrosion inhibitor for Copper and Lead Water Storage Tank Water Pumps Monitoring Control Panel
Pumphouse
Storage Tank
8000 Gallons
UV Disinfection Recycling unit
Water Pumps Water Pump Control
○
Coliforms are bacteria that are naturally present in the environment and are used as an indicator
that other, potentially harmful, waterborne pathogens may be present or that a potential pathway exists through which contamination may enter the drinking water distribution system. Presence of coliforms indicates the need to look for potential problems in water treatment or distribution.
○ Fecal bacteria from human or animal waste considered to be harmful bacteria and require immediate action.
○ Water sample results (return) are positive (present) for Coliform (TC+) and E Coli (EC+) or negative (absent) for Coliform (TC-) and E Coli (EC-). Often reported as TC-/EC- or TC+/EC-, etc
○ Well water or ground source water under the direct influence of surface water (GUDI) refers to groundwater supply sources that are hydraulically connected to nearby surface waters, and are thus vulnerable to contamination by pathogens. The vulnerability to contamination means that well water sources that are determined to be GUDI require treatment equivalent to that required for surface water sources.
○ The MPA is used to determine if there is sufficient natural filtration to remove most surface water organisms and debris, thus mitigating risks to human health. Under this method, a “low risk” determination may be used to exempt the water source from the GUDI designation. A “medium risk” or “high risk” determination will require the water source to be designated GUDI.
○ 99.99% kill rate with one pass of bacteria and viruses
○ 99.9% kill rate with one pass of bacteria and viruses
○ 99% kill rate with one pass of bacteria and viruses
Both of our wells are Shallow Wells
Utilize Ground Water as a source
Susceptible to surface water intrusion and water table fluctuation
○ TC+/EC- in distribution and Well #1 ○ TC+/EC+ in well #2
Findings
found
going to both well pumps
feet of Well #1 (and Well #2 due to hydraulic connection to Well #1) as basis of GUDI designation.
Recommended Actions
trespassing signage.
determine if Wells are GUDI
with log and monitoring protocol by QCBFD
video
Diagnostic and sampling
○ Well #2 remains offline from water system
Actions Undertaken
2019
initiated by QCBFD
the well field to improve drainage
○ Well pump removed ○ Well wall and screen mechanically and chemically scrubbed ○ Organic material and loose gravel at base of well removed ○ Bentonite seal placed around the wells
○ Well #2 returns TC-/EC- ○ Well #1 and distribution return TC+/EC- ○ Level 2 Assessment Triggered (2a-2) ○ Transmission line from Well #1 found to have a leak with root ingrowth and repaired
○ First stage of GUDI testing and both wells return low probability ■ This is a good result!
BWA
20 gallons per minute.
○ Repair of leaky transmission line from Well #1 ○ Wellhead elevation and wellfield regrade and grubbing
○ RIDOH interprets as no new correctible defects exist for L2a-3 ○ Even though correctible defect (wellhead elevation and field regrade) are still present and uncorrected at this time
plans for 4-log disinfection of entire water system.
○ Based on L2a-3 assessment not finding correctable sanitary defect.
Mid-March
○ Ordered erosion blankets and laying of grass seed
Chemical disinfection of QCBFD Public Water System
○ Technical issues outlined ■ Iron in Well #2 ■ Parasitic water loss for iron remediation ■ Possible third well looking for low iron source ■ Pumphouse enlargement and regulatory agency oversight
#1, #2, and distribution (total 9) failed as the last sample of well #1 returned TC+/EC-
developed.
1. Immediately isolated Well #2 from the water system
a. E Coli has NEVER been identified in the Distribution System; i.e water coming into your home
2. Northeast Water, C&E Engineering, RI Based, and WSP Environmental & Water Division, Connecticut based, engaged to evaluate, advise, and determine
RIDOH approved 4-log disinfection system. 3. Complied with and fully executed ALL RIDOH Level 2 Assessment (L2a-1 and L2a-2) corrective action plan
1. Evaluated design and technical issues raised by the three engineering firms
○ Excess iron in Well #2 will not allow for effective UV or chemical disinfection of water from Well #2 without removing the iron ○ RIDOH will NOT approve UV as a 4-log disinfection system and will only allow chemical 4-log disinfection (chlorine) ○ RIDOH will NOT allow 4-log, chemical or otherwise, on only one well; in our case well #1
2. Initiated clearing and grubbing of vegetation surrounding the well heads 3. Redeveloped both wells 4. Tested fill material to find low iron /manganese fill
1. Initiated fill and regrading of wellfield 2. One more attempt at sterilization of wellfield #1 3. Hope of lifting BWA (Boil Water Advisory) fades due to persisting TC+/ECI returns from Well #1 4. Responding to RIDOH 4-log system demands with engineering and technical concerns
1. RIDOH negotiations continue 2. Very clear that RIDOH will not back down from 4-log disinfection 3. RIDOH has conceded that we can initially place 4-log disinfection only on well #1 in order to achieve compliance
1. Non chemical 4-log system, although approved in CT and Mass, are not approved by RIDOH 2. Official reason is that there is no way to monitor the 4-log system effectiveness in a non chemical system 3. Chemical 4-log disinfection produces chlorine residual which can be monitored real time and an alert generated if the system is nonfunctional
a. Chlorine residual in water shows system is effective
4. UV system produces no residual so unable to generate alert in case of malfunction such as lamp burning out
1. Water quality taste 2. Chlorine Disinfection Byproducts (CBP)formation
a.
Trihalomethane (THM); haloacetic acids (HAAs) b. Function of organic compounds
3. Elevated Iron levels in Well #2 which would precipitate when exposed to chlorine disinfection and turn water orange
treatment capabilities (PFAS and/or nitrate removal)
○ Limited to iron removal ○ Parasitic water loss for back flushing (rejected water) ○ Iron sludge will need to be disposed
○ More expensive but more comprehensive treatment: ○ Addresses Total organic compounds (TOC), Arsenic, Water Turbidity, and Nitrates ○ Non chemical 4-log disinfection (Not RIDOH Approved yet) ○ Parasitic water loss is less ■ Rejected water can be repassed through membrane filter several times ○ Iron sludge is more compact can be discarded as a smaller volume
6 Year monthly Nitrate data
○ Certainly not increasing
future Nitrate rise
Nitrates
○ pH and Temperature related
○ Less NaOCl required to create HOCl (Chlorine residual) ■ 5 parts NaOCL to create 1 part HOCL will potentially allow for 4 parts of CDB
○ 1% hypochlorite solution, compared to stock hypochlorite that is typically 12% to 15% ○ More effective microbiological control, Hydrogen peroxide is also part of MIOX solution, and reduces disinfection by-products
○ Oxidation of iron
○ This should stabilize after 6-12 months as the iron sediment in the distribution lines is oxidized
Phase 1
Simple Chlorine System with monitoring
UV System 4-Log for TOC removal
Phase 2 (iron amelioration)
Media Filtration*
Membrane Filtration*
MIOX System*
* required Pumphouse Enlargement $70,000 Sourcing Low-Iron well source
○ $100,000-500,000
Ideal system
○ PH Expansion $70,000 ○ MIOX $60,000 ○ Membrane $225,000
○ Requires Community approval
○ Charter and By-laws requires in person attendance ○ No Provision for Virtual Meeting
○ Impacts ALL FD Annual and Special meetings ○ Await RI easing of public gathering restrictions
RIDOH is now demanding we chemically 4-log disinfect Well #1. Why haven’t we already installed a 4-log disinfection system? RIDOH has only recently, May 2020, allowed for us to only chlorinate well #1 and keep well #2 unchlorinated and as a backup. This is an unprecedented concession by RIDOH We tried in September to install a UV 4-log system, RIDOH would not allow it We asked in January if we could 4-log disinfect
Well #2 or chlorinate Well #2 which requires Pumphouse expansion and Iron amelioration system.
Why is RIDOH now allowing us to only chlorinate Well #1. Our professional consultants met with RIDOH in December and outlined the technical issues with chlorinating Well #2, the elevated iron well: 1. Pumphouse expansion to accommodate iron amelioration treatment
a. DEM/CRMC permitting and time
2. Parasitic water loss; the exact amount and volume to be determined with no place to discharge without contaminating the present well field
a. DEM/CRMC permitting
If RIDOH is now allowing us to only chlorinate well #1 why not proceed and be done without designing an iron amelioration system for Well #2? We cannot run solely off Well #1 and we expect that on busy summer days there may be water
conserve water usage during the high season If Well #1 should go off service we will need to run well #2 as a backup and the community must go on a Boil Water Advisory until Well #1 is back in service
Why not just find a new well source with lo-iron in place of designing an iron amelioration system? This third well proposal is being pushed by one of
a low-iron well source within our wellfield.. Several years back we explored 2 bedrock wells, with this purpose in mind, which did not yield an adequate water flow (<3 gallons/minute) Developing a new well outside of our wellfield would cost in excess of 500,000 and take over 3 years to bring online. No guarantee iron will not present in future
What if we ignore RIDOH’s demands to chlorinate? For now RIDOH has been very accommodating and reasonable in listening to our consultants present our technical issues. They are also aware of our Fire District limitations and are willing to come to a mutual agreement. If the community does not come to an agreement with RIDOH then RIDOH will issue an executive
water system. No one wishes for this to occur.
Vin Bailey Dick Campbell James Finn Bob Frazier Tom Frost Jim Montstream Fig Newton Steve Peet George Prior Greg Reppucci
Past PW Chairs:
Wally Kelly George Prior Bill Meyer Tom Doyle
And to our Moderator Sue Wilson