Presented by: David Murphy, PE, CFM. Workshop: Implementing a Drinking Water Resiliency Plan for Connecticut April 6, 2018

Transcription

1 H O W W E L L A R E W E A L R E A D Y P R E PA R E D? C U R R E N T S TAT E O F P R A C T I C E F O R C O M M U N I T Y WAT E R S Y S T E M S Presented by: David Murphy, PE, CFM Workshop: Implementing a Drinking Water Resiliency Plan for Connecticut April 6, 2018 Photo courtesy of NPU (Taken by MMI) Photo courtesy of CWC (Taken by MMI)

2 AGENDA Review of Vulnerability Assessments Review of Emergency Con9ngency Plans Review of Addi9onal Vulnerability Assessments (per the Bioterrorism Act) Small CWS Vulnerabili9es Poten9al Interconnec9ons to Reduce Risks

3 REVIEW OF VULNERABILITY ASSESSMENTS Authority RCSA Sec9on 25-32d-3(d) for CWS serving > 1,000 people or > 250 service connec9ons What Do they Say? General ranking of risks to certain types of events and/or specific consequences of events Typically recognize that certain consequences (i.e., power failure) can result from mul9ple hazards A few systems quan9ta9vely assess level of risk (e.g., high, moderate, etc.) None include Climate Change as a direct hazard (onset too slow), although other mi9ga9on efforts have the added benefit of mi9ga9ng climate change

4 REVIEW OF EMERGENCY CONTINGENCY PLANS Authority RCSA Sec9on 25-32d-3(d) for CWS serving > 1,000 people or > 250 service connec9ons Separate from the required Sabotage Preven9on and Response Plan What Do they Say? General responses to certain types of events and/or specific consequences of events Typically recognize that certain consequences (i.e., power failure) can result from mul9ple hazards None include Climate Change as a direct hazard (onset too slow), although other mi9ga9on efforts have the added benefit of mi9ga9ng climate change

5 REVIEW OF EMERGENCY CONTINGENCY PLANS General Findings Most large u9li9es have auxiliary power for cri9cal infrastructure for several days (e.g. wellfields, treatment plants, booster sta9ons, telemetry controls) Some plans acknowledge fuel availability as an issue during long outages Most large systems can meet 24-hours of demand from system storage without sources being online Many large u9li9es maintain on-call rela9onships with contractors and suppliers Most large u9li9es seek to loop transmission mains to minimizes outages during main breaks Drought response is typically a four- or five-stage plan imposing water use restric9ons as supply or storage availability declines In many cases, drought response plan structure inconsistent with 2003 recommenda9ons of Connec9cut Drought Response Plan

6 Key Findings REVIEW OF EMERGENCY CONTINGENCY PLANS Most ECPs are response checklists that do not provide specific examples of poten9al mi9ga9on measures for many events The rela9vely general response procedures in the ECP allow for flexibility in response by the u9lity Climate change has consistently not been addressed, as the ECP is typically focused on response to short-term emergency situa9ons (and drought) Most large systems can func9on for at least 24 hours with just storage Rela9vely few groundwater sources are floodprone Inconsistency between number of drought response stages could be confusing

7 ADDITIONAL VULNERABILITY ASSESSMENTS Authority Bioterrorism Act of 2002 required: Prepara9on of a Vulnerability Assessment (VA) and submiaal to EPA Prepara9on of Emergency Response Plans (ERPs) What Do they Say? These are secure documents; only a handful were available for review Focus is clearly sabotage (internal and external) and terrorism A few of the resul9ng ERPs aaempted to incorporate natural hazards from the Emergency Con9ngency Plans

8 Background VULNERABILITIES OF SMALL CWS Approximately 160 small CWS in the four southern CT coun9es that are not affiliated with a large water u9lity Public water systems lacking redundancy in sources, transmission, storage, or pumping are typically less resilient than those with redundant cri9cal assets Small CWS typically lack the resources and redundancy of larger CWS and water u9li9es Nearly all assets are cri9cal in a small CWS DPH has developed a Capacity Assessment Tool (CAT) to evaluate capacity of small CWS

9 VULNERABILITIES OF SMALL CWS Some Stats on These 157 Systems 99% are well systems, remainder are interconnected systems without sources 10% are interconnected with another system or u9lity 9% have contact tanks for disinfec9on 57% provide some type of water treatment 55% u9lize booster pumps 61% have atmospheric storage tanks 53% have hydropneuma9c storage tanks 40% have bladder storage tanks

10 Some Stats on These 157 Systems 99% are well systems, remainder are interconnected systems without sources 10% are interconnected with another system or u9lity 9% have contact tanks for disinfec9on 57% provide some type of water treatment 55% u9lize booster pumps 61% have atmospheric storage tanks 53% have hydropneuma9c storage tanks 40% have bladder storage tanks VULNERABILITIES OF SMALL CWS These are really low! Low capacity of redundant supply Only 15% of systems chlorinate (if no tank, injec9on is used) What does this mean? Some have mul9ple types (atmospheric & hydropneuma9c) Some have mul9ple pressure zones 7% do not have pressurized storage 3% have no storage at all (most of these are consecu9ve systems)

11 Key Findings VULNERABILITIES OF SMALL CWS Most small CWS have one bedrock wellfield as a source of supply The volume of available storage varies considerably, from zero to 30 gallons to 10s of thousands of gallons Many small CWS cannot disinfect, and electricity is required for treatment Many small CWS do not have interconnec9ons, either due to isola9on, lack of funding, or by choice

12 InterconnecAons VULNERABILITIES OF SMALL CWS Installing addi9onal supply sources or redundant infrastructure is not feasible for many small CWS due to funding, environmental, and hydrogeological factors or simply space constraints Small CWS within 1,000 feet are poten9al candidates for interconnec9on to increase redundancy and resiliency Interconnec9ng mul9ple small systems to a large system or u9lity greatly increases redundancy and resiliency Results 93 poten9al interconnec9ons iden9fied to improve resiliency Ø 40 of these are within 100 feet of the nearest system! 40 poten9al interconnec9ons iden9fied between small CWS and large CWS Interconnec9on is feasible for the majority of small CWS with low CAT scores

13 POTENTIAL INTERCONNECTIONS NEW FAIRFIELD, CONNECTICUT

14 POTENTIAL INTERCONNECTIONS CENTRAL CONNECTICUT

15 POTENTIAL INTERCONNECTIONS LEDYARD, CONNECTICUT

16 QUESTIONS